Does Marijuana Cause Schizophrenia?

Repost from the old site.
One of the longstanding arguments against the use of marijuana is that is causes mental illness, in particular psychosis. For a long time, cannabis was said to be associated with a particular entity called “cannabis psychosis”. This entity has not been proven to exist.
Cannabis has also been said to be associated with depression and anxiety. Some people do experience anxiety when they use cannabis. In many cases, they used it for some time before an anxiety reaction started. A cannabis panic or “paranoid” reaction is quite common amongst all types of cannabis users. Generally, users who start to regularly get panic reactions tend to stop using the drug.
Anecdotally, many persons report relief from anxiety, depression, tenseness and anger from the use of marijuana. A friend of mine who was in jail for marijuana said he met many angry prisoners who used marijuana to reduce their anger. I known young males who are chronically “hyper” – tense, restless and on the verge of anger. Regular marijuana use works well to completely alleviate this condition.
In recent years, some frightening studies have come out connecting cannabis to psychosis, in particular to schizophrenia. On the surface, there would not appear to be much grounds for alarm. As you can see in my previous review on the subject of cannabis and brain damage, heavy use of cannabis, of all the intoxicating drugs, seems to be easiest on the brain.
This does not mean that it has no effects on the brain at all, but instead that heavy use of all of the other intoxicants is harder on or riskier to your brain than heavy use of cannabis.
Since heavy cannabis use is so much easier on your brain than heavy use of anything else, how is it then that cannabis should be associated with schizophrenia, while the other more harmful drugs are generally not? This is a bit of a mystery.
Promoters of the pot-schizophrenia link have suggested cannabis’ effect on the dopamine system – that is, it releases dopamine. Yet almost all drugs release dopamine, including alcohol, cocaine, methamphetamine, etc. In fact, coke and speed are far more dopaminergic than cannabis. Truth is that anything pleasurable releases dopamine – sex, chocolate, a good movie.
Animal models have not been particularly helpful in determining the relationship of cannabis to mental illness.
One recent animal model showed that not only did cannabis cause mice to actually sprout new neurons in the hippocampus, but it also reduced measures of depression and anxiety. Opiates, tobacco, alcohol and cocaine all reduce neurogenesis in the hippocampus. The reduced depression and anxiety seemed to be caused by the neurogenesis. Cannabis also protects mice against brain cell death caused by alcohol.
There is also evidence that cannabis is protective against the neurotoxic effects of stroke and head injury. Further evidence shows that cannabis is effective in slowing the progression of various neurodegenerative diseases such as Alzheimer’s, MS, Parkinson’s, and ALS (Lou Gehrig’s Disease).
Given the evidence that cannabis does not seem to do much bad to your brain, and if anything seems to be neuroprotective and even neurostimulatory, it seems odd that this drug should be connected with such a devastating brain disease as schizophrenia.
Nevertheless, the evidence seems to be there, and it is quite frightening to look it over. The initial study was an elegant analysis of Swedish military recruits in 1987.
The increased risk was on the order of 4.5 times for those using by age 15, but down to 1.6 times for those using by age 18. The increased risk was decreasing rapidly. Let’s extrapolate to ages 16 and 17: Age 15: 4.5 X. Age 16: 3.7 X Age 17: 2.65 X. Age 18: 1.6 X. At that rate, all increased risk would have evaporated for users who wait until they are age 19 until they start using.
Since the Swedish study, the evidence has piled up. Still, despite the scary and numbing evidence, there is not yet any evidence that cannabis causes schizophrenia de novo. Instead, it appears to be interacting with some already existing risk factor.
This page is a good repository for the numbing evidence on this score.
However, that site has some serious problems.
They are finding increased risk of schizophrenia from everything from “being too introverted and being alone too much”, emigrating to a new country – up to 4X increased risk, having an unpleasant and unstable home life as a child, experience – social adversity – four or more episodes of “abuse” increased risk by 2.7X, living in a city (3X increased risk), especially an inner city (as opposed to the country), or being vulnerable to depression or anxiety.
In order to avoid schizophrenia, according to the site, one would have to never go live in a new country, never spend a lot of time alone or be an introvert, never move to a city or an inner city or never grow up in one, be robust in handling stress, experience little social adversity, and somehow assure that one had a happy and stable home life as a child.
At some point, you just have to live your life and these kind of “risks” be damned. Personally, I am dubious that any of these things actually contribute to schizophrenia.
A person slowly developing schizophrenia over years tends to spend a lot of time alone, become introverted, move to a major city (often the rundown inner city part), wander around the country or parts of the globe, experience a lot of social adversity and handle stress quite poorly as the disease slowly unfolds.
Their relatives often show various degrees of the illness themselves and this probably accounts for the problems in childhood experienced by mildly effected parents. Either that, or the person at risk of schizophrenia is already odd, hostile or combative, and this causes a poor parental relationship.
Even if cannabis did increase the risk of schizophrenia, there seems may be an age effect. Robin Murray found that first use at age 15 increased the risk of schizophrenia by 4 times, while by age 18, the risk had dropped to 1.65. By this trend, one assumes that at some point after age 18, the risk would drop to zero. Assuming the risk is real, it could be substantially ameliorated by avoiding cannabis until one is 18.
In general, most studies found about a doubled risk of schizophrenia from cannabis use. It is interesting to note that chronic heavy drinking was even more of a risk to psychosis than heavy cannabis use, increasing the risk by four times.
It has become clear in recent years that schizophrenia, when occurring over a period of years, is correlated with serious damage and disruption to the brain in a wide variety of areas and manners. The notion that a meager drug like cannabis could actually cause such dramatic dysfunction and damage is ludicrous.
The only thing that could possibly be happening here is cannabis triggering, or setting off, a cascade that begins the neurodegenerative process known as schizophrenia.
The pot-schizophrenia theory was recently blown up again by a truly absurd study. An MRI study showed that subjects given THC showed reduced activity in the inferior frontal cortex. This area controls inappropriate emotional and behavioral responses to situations. The more the activity was reduced here, the more paranoia the subjects experienced.
Somewhat bizarrely, the study claimed that pot-induced “paranoia,” which most users are familiar with, is synonymous with “psychosis.” They said that 50% of the users “became psychotic” and experienced schizophrenia-like symptoms. That is obviously idiotic. If that is psychosis, then every marijuana user I have known (thousands) have been psychotic many times.
The major problem with all of the studies showing a link between pot and schizophrenia is that we should have seen an explosion of schizophrenia in the West during the 1960’s and 1970’s. Instead, the rate was flat or even declined.
Advocates of the pot-schiz link such as Murray have all sorts of reasons why either rate has actually gone up when we found it didn’t, or it’s going to go up in the future, or finally, that even heavy pot use by millions of citizens will only increase the rate of schizophrenia by 14%. This absurd and totally unproven “14%” figure is now being bandied about by the media (see below).
This study from Australia concluded that since the incidence of schizophrenia has not risen with the explosion in cannabis use, cannabis cannot be said to cause schizophrenia. Instead, the study said cannabis appears to be triggering it in people who would have ended up schizophrenic anyway. However, cannabis use may worsen the course of schizophrenia in those who already have it.
The study was unable to conclude that cannabis use brings on schizophrenia quicker in those who would develop it anyway, since they found no trend in decreasing age of diagnosis, even with the explosion in cannabis use in recent years. However, this study did find that cannabis-using schizophrenics developed symptoms sooner than those who did not use it.
On the other hand, this may be explained by the very common phenomenon of heavy use of cannabis during the prodromal phase of schizophrenia. Another study suggested that cannabis use may be causing schizophrenia in people who would not otherwise develop it, but the lack of increased diagnosis would seem to argue against that.
Yet another Australian study concluded that cannabis precipitates and worsens schizophrenia in those who would have developed it anyway.
Much of this data is from a group of psychiatrists in London (centered around Robin Murray – see above) who are convinced that marijuana is increasing the incidence of schizophrenia in the UK.
They have produced data showing that the rate of schizophrenia has gone up in their inner-city neighborhood in recent decades. However, that increase is at odds with studies done over much of the rest of the world in recent decades.
The same researchers produced another “definitive” study that “ends the debate” about whether or not marijuana causes schizophrenia. It reviews a number of studies and shows that every study does find increased psychosis with increased marijuana use. It then predicts that 14% of all cases of schizophrenia in the UK are being caused by pot use. This conclusion is unwarranted.
First of all, there is indeed an association between pot use and schizophrenia (in my opinion, especially under age 18 and particularly under age 16). However, as you can see below, the rate of schizophrenia in general has been either flat or declining all through the cannabis epidemics of the past 40 years in the West.
Therefore, it is premature of the UK researchers to claim as yet that pot is causing 14% of schizophrenia cases in the UK.
A paper out of Micronesia dated 1993 noted that schizophrenia had increased dramatically in the previous 20 years. There had been an attendant increase in the use of marijuana and other drug use.
The Australian study above, one of the best studies done to date, completely rejected the notion that cannabis causes schizophrenia in persons who would otherwise not develop it, but did suggest that cannabis use may bring on schizophrenia sooner in those who were going to develop it anyway.
Heavy cannabis use does seem to be particularly problematic in early adolescence. Kids that age should not be using cannabis anyway.
The Australian study also suggested that cannabis worsened the prognosis of schizophrenia, but that the effect was not a large one. Studying this variable is difficult since the younger one is when schizophrenia comes on, the more likely the person is to relapse, and young people are the most likely to be cannabis users.
So cannabis use and relapse to schizophrenia are going to be co-occurring due to age alone. Nevertheless, there seems to be good evidence that schizophrenics need to stay away from this drug.
The one hypothesis that shines through most clearly in all of these studies is that schizophrenics tend to be more likely to use cannabis, and more likely to use it heavily, than non-schizophrenics. In other words, simply being schizophrenic increases the likelihood of cannabis use and dependence. We can surely agree with this theory – it’s not controversial at all.
Along the lines of the Australian study, we can look at tobacco use and lung cancer. As cigarette smoking skyrocketed, lung cancer went through the roof. As smoking declined, lung cancer rates also declined.
No such picture is being seen with cannabis and schizophrenia.
Another recent study is getting a lot of media play with a totally unwarranted pot-schiz link. It found an altered development of the arcuate fasciculus, a bundle of fibers connecting the Wernicke’s and Broca’s Areas of the brain, one involved in the production of language and the other involved in the reception of language. Photo of the arcuate fasciculus is here, and a schematic is here.
Damage to the arcuate fasciculus is associated with a particular type of aphasia where language can be produced and comprehended well, but if you say something to the sufferer, they cannot repeat what you just said. The arcuate fasiculus is still developing in early adolescence, but it is not known if it continues growing in through late adolescence.
Lower volume was seen on the left side of the arcuate fasiculus in adolescent heavy marijuana users. In schizophrenia, there is reduced volume on both the left and right sides of the arcuate fasiculus. Defects in the arcuate fasiculus in schizophrenia have unknown significance, but the structure is abnormally activated, along with some other areas, during auditory hallucinations.
Excessive activation of the arcuate fasiculus associated with auditory hallucinations would not likely be caused by a reduced volume to the structure. With reduced volume, there would probably be less activation.
Damage to the brain in schizophrenia, as noted above, is quite vast and covers widely disparate areas of the brain, involving multiple structures.
Some areas are abnormally activated, while others are abnormally dormant. There are problems with various neurochemicals in the brain and receptor alterations in the cells themselves.
In short, schizophrenia is a disease caused by massive damage to the brain. One recent study likened it to a forest fire in the brain.
The problems in the arcuate fasiculus are but a tiny subset of the massive organic damage of schizophrenia. The fact that the arcuate fasiculus may be damaged by heavy cannabis use in adolescence is disturbing, but it hardly proves that such use causes schizophrenia, because schizophrenia requires much more damage than that.
Further studies using DTI found no abnormalities whatsoever in any part of the brain. In fact, if anything, adolescent cannabis users tended to have larger brains, with more cells (white matter) than the controls.
That doesn’t mean that using cannabis in adolescence makes you smart, but it surely rules out significant organic structural brain damage, and it does add interesting weight to the neuroprotective and neurostimulatory papers above.
Furthermore, many reports of “cannabis psychoses” do not appear to be psychoses at all. This preposterous report of two cannabis psychoses, published in a respected peer-reviewed journal of all things, is illustrative.
Looking over the paper, Case 1 appears to have just gotten really stoned. If that’s “cannabis psychosis”, then I’ve been “psychotic” on cannabis hundreds of times, and I must have witnessed thousands of other “cannabis psychoses”.
Case 2 is a bit more difficult, as he became suspicious of the testers at one point. It’s well known that cannabis users can feel frightened and even “paranoid.” Lord knows, I experienced it many times myself. However, the man merely felt that the testers were “concealing problems” from him. That really does not qualify as a paranoid delusion.
The world is full of suspicious people. At times, I’m pretty suspicious and wary myself, for good reason, I would say. The vast majority of people even with pathological suspicion or paranoid ideation are not suffering from paranoid delusions.
Furthermore, the questions that are asked on questionnaires of cannabis psychosis are dubious. “Most people cannot be trusted.” Well, if you live in the ghetto or the barrio, that’s a damn good attitude!
“Sometimes it seems like people are looking at me and talking about me.” Look, as you go about your business day to day, it’s quite possible people may take notice of you in one way or another.
At times people may indeed talk about you, sometimes within hearing distance. It’s hard to say whether they are talking about you in a friendly way or not. Sometimes they may seem friendly; other times not, but mostly of the time, they will probably just seem neutral.
A typical psychological questionnaire will ask you questions about many of these things. If I answer yes to any of them, it gets chalked up to “paranoia.” I know because I have taken these tests.
If you act strange in any way, people are much more likely to stare at you and even talk about you behind your back. So if everyone who acts odd enough to get stared at is hip enough to recognize the obvious, that means they have a paranoid psychosis?
There are indeed folks out there who seem to others to behave strangely. In our society, they may be called nerds, nervous, weird, or shy. Perhaps in Japan they fit right in. There are folks who live alone, never marry and even folks who never date. I’ve run across quite a few “odd” folks in my life who were not psychotic in any way. Most were not even mentally ill.
Now, I can assure you that these folks are going to get stared at from time to time, and people will even talk and whisper about them behind their back. If they happen to be self-aware enough to notice this, does this mean that they are paranoid?
In conclusion, there is some frightening stuff out there about pot and schizophrenia. At the moment, it should be read with caution. A judicious approach would be for adolescents to wait until they are at least 18 and possibly even older until they start using cannabis.
The available evidence indicates a rapidly declining risk towards the end of adolescence that presumably declines to zero increased risk at some point probably soon after age 18.
Even there, though, the Swedish study found that heavy users by age 18 were six times more likely to develop schizophrenia than non-users. So if you are going to use cannabis heavily, you should wait until you are at least 19, and possibly even older.
Prudent cannabis users will wait until they are at least 19 and then not use the drug every day. Those using or beginning to use the drug later in life, for instance me at age 50, surely must have zero increased risk of psychosis. Further research will presumably elucidate some onset age at which use of cannabis is not associated with any increased risk of schizophrenia.
I would also like to recommend a similar area of research: medical cannabis. There are many medical cannabis users now in various countries. Many of them are older people, as these are the ones who tend to be more injured or ill in life.
An interesting study would determine precisely how many of these medical cannabis users are developing schizophrenia. I have not heard of a single case so far. The number of cases must be quite small.
To add a personal link:
I used cannabis for about 22 years off and on since 1973.
All these psychiatric reports anger me because at my age and with my mental state, cannabis use dramatically improves my mental health. Many others report similar benefits. The notion that cannabis always or almost always causes deterioration of mental health is utter nonsense, and I am getting sick and tired of hearing of it.
Sure, it’s bad for some people, but look around the Net and see how many people are using it to treat anxiety disorders, eating disorders, mood disorders, etc. Does it not stretch credulity to think that all of these people are just making stuff up?
All my friends were pot smokers, and many were potheads. I also sold drugs, mostly pot, for 14 years, never got caught (neither did the vast majority of my friends) and don’t regret a thing. Actually, being a dealer was kind of fun.
Not only did I never experience any psychotic symptoms while using cannabis, I have never experienced any while off of it either. Further, I have never seen one single case of psychosis attributed to cannabis, much less schizophrenia, and that includes probably thousands of pot smokers over decades, including hundreds of heavy users, many of whom used for many years.
Based on my own experiences, any risk of schizophrenia due to cannabis is not likely to be large.
I have known a few people with schizophrenia, but not many. I was good friends for about a year with a paranoid schizophrenic who heard voices much of the time until people told me to get away from him. He had only smoked pot a couple of times and did not like the drug.
I know of one schizophrenic, ill from an early age, who loved to smoke pot. But it made him a lot worse, so everyone tried to keep him away from it. Interestingly, his brother, surely at risk of schizophrenia, was a dealer and very heavy cannabis user for many years, never developed schizophrenia and was reasonably well-adjusted.
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158 thoughts on “Does Marijuana Cause Schizophrenia?”

  1. Whether cannabis sends you nuts has a lot to do with what kind of cannabis you smoke. In London, at lot of the kids smoke super skunk weed, which is designed to be very high in THC. I’ve smoked it and I can definately feel that in would turn a young mind inside out. On the other hand, the kind of stuff you’d get in the in the 60s and 70s was a more mellow and rounded drug. It’s the difference between having a light beer and drinking a bottle of vodka.

    1. Cannabis, even skunk weed, does not seem to do much to the mind of an adult. Sure, it’s strong and the high is rather psychedelic-like, but I love psychedelics. OTOH, a lot of people can’t handle such mind-bending states. The truth is that as even skunk weed doesn’t seem to do much to your brain, how is it that pot can cause schizophrenia, seeing as schiz seems to be a disease caused by extensive brain damage. None of it makes any sense.

  2. What a brilliant article, forthright, frank, honest and backed up by solid arguments proving that such speculation about cannabis and mental illness is more likely to cause mental illness than the cannabis itself.

    1. so, you sold pot and dont regret it? Have you ever stopped to think that you sold to kids who now have developed schizophrenia? your are an asshole.

      1. how do you know what kids he sold to and if they developed schizophrenia? Do you think every store that sells tobacco and alcohol are ass holes because people may develop health issues because of it? How about a car dealer? Should they feel bad because a person might crash them selves in the car they sold them and die? You’re completely one sided. I’ve sold it and i don’t regret it. Still love marry jane always will

        1. Your comparison to the car dealer is way off
          And the world would be better off without alchohol, marijuana and illegal drugs.
          Hopefully the awful illness of schizophrenia will not touch your life or your loved ones. If it does, know that smoking pot will make it far worse (even if you don’t believe that that could have possibly triggered it)

      2. as the author of the post made clear just because you smoke does not mean that you will develop schizophrenia. However, if you do have a genetic predisposition to the disease frequent consumption of marijuana as an adolescent can cause increased chance of developing schizophrenia. It is also important to keep in mind that the exact causes of schizophrenia are unclear. I might be wrong but I remember seeing in a documentary that it is thought to be caused by the expansion of water sacks in the middle of the brain, which forces certain other parts of the brain against the wall of the skull causing hallucinations, disembodied voices, and paranoia.

      3. hank your an idiot. I’m glad the children spent their money on pot instead of crack or all the pills available to them. your playing make believe with kids life. I sure don’t want you dispensing advice to my children.

  3. I enjoyed the read but if you smoke marijuana and find that you are becoming tired and de motivated and you do not want to quit using marijuana. Try vaporizing your marijuana and you will get more a of a clean headed high buzz.
    Like tobacco, marijuana smoke contains toxins that are known to be hazardous to the respiratory system. Among them are the highly carcinogenic polynuclear aromatic hydrocarbons, a prime suspect in cigarette-related cancers. These toxins are essentially a byproduct of combustion, separate from the pharmaceutically active components of marijuana, known as cannabinoids, which include THC. When you burn marijuana it produces quite a lot of tar. Pipes and joints generally do not have proper filters. Bongs are not the answer, because you inhale concentrated smoke.
    The vaporizer certainly reduces the level of tar. You will not have to worry about the harmful carcinogens your body is absorbing when you inhale marijuana smoke.
    I will suggest 2 places that I use the first one is Legal Bud!
    The second suggestion I have is Gass City!

    1. Then why has there not been one case of lung cancer from someone who only smokes pot? You may want to check your facts before shooting out your ideas as truth to the world. The inside of a pipe does not clean itself, your lungs do. Can’t really compare pipes to lungs when it comes to tar build up. Resin is not tar, google it. If you buy your shit imported, you never know what they use to mask the smell or other contaminates that get in. But if you grow it yourself or buy from local growers then why would you/they add any chemicals to the finished product? If all your smoking is marijuana then most likely it will not be the definitive cause of any cancer or terminal illness. Kids under 18 should not smoke pot with out knowing all the facts. Any mind altering substances (prescriptions drugs included) will have a effect on any minor. After the mind has matured to adulthood, I really don’t see any evidence that proves marijuana is the sole cause of any medical problem. There are theories for and against marijuana, but that is all they are right now, just hypothesizes, you should decide for yourself and not give people incorrect information.

      1. You may want to check your facts as well. Though the link between marijuana and cancer is one that is still very much up for debate there is no doubt that many studies have linked the smoking of cannabis (without tobacco or any other additives) to various types of cancer including lung, testicular, and bladder. Also, as a previous poster pointed out marijuana does contain carcinogens (pretty much anything that creates smoke does) and on top of that any hot vapor that is inhaled can singe the alveoli of the lungs. In conclusion, feel free to enjoy smoking your marijuana just don’t try to say that it is some magic substance that has no side effects (everything has side effects).

  4. The reason why I read this article is because im getting worried. I smoke a lot of marijuana and recently, in the past couple weeks, I have been experiencing tons of symptoms oh schizophrenia and I dont know why. I have been hearing things in my head that no one else hears and even seeing things no one else sees.I had to read this article to see if there was link between these two things. I guess there is.

  5. I am a 17 year old, regular cannabis user and am writing because I think that an adolescent voice could be helpful in analyzing the subject of marijuana. First off I would like to say that I agree with Robert Lindsay’s view that the assumption that marijuana typically causes mental damage is a ridiculous accusation and personally I find it offensive. However, I do agree that my regular use of cannabis has changed my mental state. I find it difficult to explain this change but I can say that in no way has it made me worse off. It has not negatively affected my athletic or academic performance in any way. In fact I would argue that it has enhanced my academic performance especially in the area of english. However I could see how the modern and seemingly world wide view that marijuana is a terrible drug that harms and ruins lives could get so blatantly mislead. Of course I believe that when under the influence of marijuana, it becomes difficult to express my thoughts. However I think that the decrease of ability to express thought simultaneously occurs with the increase of ability to articulate thought. As an outsider or spectator of a stoned person, this could quite easily come across as limited brain activity, even though this is not the case at all. I find that it is because of this why people are so quick to agree with the common belief that marijuana is bad.
    I have a couple of questions regarding this article.
    1. You use the term “heavy cannabis use” a lot, what does this mean?
    2. Though it seems hard to comprehend and believe that marijuana could be linked or potentially cause schizophrenia. That swedish military study is enough to scare me. It seems to me that this is a rare case in history that shows possible signs that marijuana use has caused schizophrenia. Is it likely that in sweden during the 80’s their could have been a concentration of extraneous factors that may have mislead people into thinking their is a link between marijuana use and schizophrenia?
    3. Lastly, when you say that
    “The increased risk was on the order of 4.5 times for those using by age 15, but down to 1.6 times for those using by age 18. The increased risk was decreasing rapidly. Let’s extrapolate to ages 16 and 17: Age 15: 4.5 X. Age 16: 3.7 X Age 17: 2.65 X. Age 18: 1.6 X. At that rate, all increased risk would have evaporated for users who wait until they are age 19 until they start using.”
    What does X represent? And also when you say that marijuana smokers that start during the age of 15, does this mean tried it for their first time during the age of 15 and continued rarely, or does this mean tried it and then it quickly became a habit?
    Sorry to make this so long it’s just that I have a lot to say on this topic and your article really interested me. Thanks a lot.

    1. 3. X is baseline schizophrenia risk. Anything above X is increased risk.
      2. I don’t think so. It *does* look like there is some sort of a risk with early cannabis use. All it’s doing is bring on schizophrenia sooner in people who would have developed it anyway! I’m not 100% sure that it is ALWAYS bringing it on sooner and never causing it in someone who would never have gotten it, but that’s what it looks like. Thing is, the rate is schizophrenia is not going up! Bottom line. Even with the explosion in MJ use.
      1. Heavy cannabis use was a stupid term in their study. If you used 50 times, you were a heavy user. Use 50X by age 15, heavy user. Use 50X by age 18, heavy user. Kind of stupid.
      I’m not a big fan of adolescents using pot, though I used it myself from 16 on and had a blast, we didn’t have access to the recent studies that you guys do.
      If you’re worried about cannabis and schizophrenia, I recommend quitting smoking pot at the moment, and then starting it up again at age 19 (if you wish), when theoretically all SCZ risk should have evaporated.

  6. Well, you can use this as you want and it may be wholly anecdotal, but it is what happened to me.
    I have a family history of mental illness. I was a reasonably well functioning teenager in high school. I had healthy sleep and hygiene habits. I was an honor student and a National Merit Scholar. When I went to college I fell in with some heavy marijuana users and began smoking marijuana everyday, many hours a day. Within months I developed severe psychotic-type symptoms that I had never experienced before. These symptoms ranged from paranoia to anxiety to disorganized thinking. Smoking marijuana started to trigger extreme anxiety bordering on panic and entirely irrational beliefs about my personal safety. I suspected a connection and stopped using marijuana however the symptoms did not diminish.
    I began to exhibit psychotic behavior and I was paranoid and uncomfortable in my dorm room. I started to sleep all day. I stopped attending classes. Mostly I just wandered around the city on foot because I felt severe discomfort in the presence of others. I withdrew from the social environment of my university and returned to my parents house.
    The next several years were tough. I went two years without leaving the house except for very short trips. I stopped talking to all of my friends. My hygiene practices worsened and I began to only get out of bed in the wee hours of the morning. My thinking was very disturbed. I began to see a psychiatrist, was diagnosed with schizoaffective disorder and started on a hearty dose of anti-psychotics and SSRIs.
    I eventually returned to school but was quite low functioning. It took me ten years to earn my undergraduate degree. In the subsequent years I have continued to struggle with my disorder. I have been hospitalized in long term facilities more than once. I am 30 years old and struggle to support myself. I still live with my parents.
    I currently take medication to keep psychotic symptoms at bay.
    It may be that my diagnosis was inevitable. However, I think that the possibility that heavy marijuana abuse triggered or exacerbated my condition is certainly worthy of investigation. If, as some suggest, egregious marijuana abuse can result in a condition of this sort it would be irresponsible not to publicize the relationship so that others with a history of mental illness in their families could take precautions.

    1. I am very sorry for your predicament. Although I don’t have a psychotic illness, I have an anxiety disorder called OCD and as a result of it, most people think I’m a pretty strange person. So I can relate to a lot of what you are going through except it is possibly even worse than what I experience.
      I don’t recommend that any young person get involved with smoking marijuana for many hours a day, as you put it. That’s just completely nuts. There’s no way that that is going to be good for your mind or body.
      At that age, I was smoking pot maybe once a week or so. Most 18-19 year olds ought to be able to handle that pretty well.
      The problem with the pot causes schizophrenia thing is not only that pot is the mildest of all intoxicants as far as being easy on your brain, but that the rate of schizophrenia has not gone up at all, while cannabis use has gone through the roof.
      I do agree that it is probably bringing on the illness sooner in folks who would have developed it anyway. But that means that you may have had years of good functioning and fun life before illness set in.
      I’m sorry you’re ill, but as you organize your thoughts quite well on here, I think you are not nearly as bad off as many others. Good luck to you!

  7. Hello
    When I was younger, I didnt have a close relationship with my family and my parents were heavily involved with the community, hence worrying about their reputation.
    I felt pressured to act and dress a certain way and went with it easily, however after smoking pot felt confused as to how to act and how to show other feelings. I became angry and your ‘ typical’ 14 year old.
    I could always hear my parents bicker about me from my room and felt like number two; in the sahdows of my super smart and world champion wrestler brother.
    I feel like all the pressures started to form negative words in my head and I started to become psyhcotic.
    Seeing things. Feeling ghosts, yes, communicating with them, Hearing terrible thoughts non stop blazing in my head. Words like, pussy, bitch, slut, loser.
    I knew that they were not true and tried my darndest to meditate for any length of time possible.
    I was a national competitor in soccer and kayaking. I started meditating at age 10 and believed in god.
    I made it a matter of good and evil and evil was not going to win me over.
    It was all I had.
    I quit smoking pot and my severe paranoia, dilusions and agoraphobia went on for a few years.
    I went to university.
    My parents wouldnt let me get help. No teachers listened. My dad threatened a principle when I was in kindergarten( olympic wrestler) becasue I couldnt role my rr’s in french and maybe teachers didnt want to go there.
    I am happy about it though, cuz I am against medications. I had friends on meds and they were sorta melancholy.
    I did some of my best art and enjoyed the craziness sometimes. But it was hard. I had to BELIEVE that I was going to get thru it soo hard that it became true.
    I believe I beat schitzophrenia thru belieing in myself and in god. I am not religious. Just spiritual.
    No one helped me. I was soo alone.
    It was so hard.
    I quit smoking for a long time and started again 10 year later.
    It was all good for a year until I started hearing things again and getting ridiculously uncomfortable. When uncomfortable, people notice(I am very pretty, so people look), and then people judge.
    when I am high, I cant deal with judgements. I am a confident young woman.
    But I wonder If maybe I am not and when I am high, the real veil is taken away and the true colors are revealed?
    I am all about truth and that is what turned me on to the hell.
    But now, I realize I dont want to toy wiht the devil anymore.
    I have a man that loves me and I have what I alwasy wanted. Love.
    So I quit for good this time:)
    I have pretty high on life as it is;)
    Thank you

    1. Jesika everything you have just described is what I am fighting through right now. I always felt like the under dog all through my life and sought answers to my problem through maurijuana. I created this whole fantasy world in my head with mythologies and delusions just to escape from reality and the weed just made it even worse. I’m not sure if you felt the same under the effects of that drug, but I have a feeling that you felt incredibly alone and paranoid, hounded by unseen forces and your own illusions, thats how I felt..
      Your statement about the true colors being revealed hit home the hardest. I too have felt the same and when I am high it is almost undeniable that it might seem that way. However I am certain that those “true colors” are just lies and the veil is nothing but our imagination playing a dirty trick on us.
      After trying it for the 8th time and finally realizing what it had done to me, I told my parents about it in order to break the spell, and before too long I realized the delusions followed my sobriety and gave me anxiety into the long hours of the night.
      I have been a month clean and am still currently discrediting the delusions I created for myself. Your post gave me the hope that if someone else did it I surely can! Thanks Jesika for the inspiration.

  8. My girlfriend has been smoking pot since age 14, several times a month and has done LSD several times in her life. She has a family history of schizophrenia, being her second cousin. She is now 21. How likely is it that she will become schizophrenic??? Is there any way she won’t develop it or is she already screwed??

    1. Several times a month is not that much.
      Second cousin is not that close of a family member.
      The chances are overwhelming that she will NOT develop schizophrenia. Even most people with a family history of schizophrenia can smoke pot and take acid without developing schizophrenia. At this point, her risk from pot is over. It’s over by age 21. Whatever risk she incurred, has already occurred. At this point, she can smoke all the pot she wants and continue to drop acid with no additional risk of developing schizophrenia.

    2. I can’t believe this person (Robert Lindsay) is giving such an awful advices. I have been reading this comments and he is indeed giving awful replies. This goes to TOM. If your girlfriend’s family has some history of schizophrenia cases, your girlfriend is more likely to develop it too. Tell her not to smoke AT ALL.

        1. Don’t be so hard on people who suggest not using pot. It is true that not every person who smokes will develop schizophrenia, but some people will develop the disorder as a result of smoking even once. The research HAS SHOWN THIS. Both my father and my brother have schizophrenia and if you saw how devastating the disease is, you would most likely agree that even helping one person avoid it is worthwhile. I have smoked pot once in the past am now 22 (the age at which women usually develop the disorder). I live in terror about developing psychosis, and have already thought that I observed some symptoms developing. I also just got into graduate school, which means that if I do develop the disorder my whole life and a lot of hard work have been for nothing. If you want to smoke pot, by all means do. Just do not tell others to do it!

          1. Thank you dear. What are the symptoms you are getting that you think might be symptoms of it? If you don’t want to tell me on here, feel free to email me. I am very good at looking at this sort of thing as I work with mentally ill people.

  9. Isn’t the fact that using marijuana is a crime reason enough to develop feelings of anxiety and paranoia? I know driving home from my dealers house with an ounce made me terribly anxious, however for a brief period it was legal in Ontario and during that time all feelings of anxiety and paranoia left my mind. It was as though a huge weight had been lifted off my shoulders. Now that its a crime again and new laws with mandatory minimums are on the horizon along with the D.E.A. not respecting our sovereignty, I feel like I’m being crushed.

    1. I too feel that society’s demonization of this harmless drug has created a certain amount of paranoia. spending 1 night in jail does a whole lot to bring on skedso incidents than weed ever will.

    1. Interesting they mention alcohol, but don’t mention asking the Swiss soldiers about their alcohol use. That’s about as lame as Dr. Heath’s study on cannabis killing brain cells.

  10. First, very nice article!
    You are missing what is, I think, the most compelling piece of evidence that cannabis use doesn’t cause schizophrenia: the tobacco-schizophrenia link.
    its a wiki article but it sums up the evidence nicely: 80% of schizophrenics smoke tobacco, compared with 20% of the general population. using the same logic as people linking cannabis and schizophrenia, tobacco is many times worse.
    Every scientific study and popular media article touting a link between weed and psychosis is glaringly lacking without mentioning that tabacco has perhaps a much more obvious link.

  11. Hi
    my brother start smoking weed about 10 years ago. i am assuming he was a heavy smoker meaning smoked almost everyday. at some point i do believe he smoked everyday.
    he start hallucinating and talking about demons and how some people tried to kill him .
    we took him to a doctor and was diagnosed with schizophrenia and was given medication .
    we have been monitoring him for a while , but he always goes back to smoking. when he doesnt using marjuana he is normal some what , he does not have those hallucination .
    two days ago my other brother took him to NYC with him for only 2 days . when he came back he was a different, he was hallucinating and jumps from one topic to another. he would start talking about how hot it is then how he saw an elephant or how they make burger or buy casio cars . my 2nd brother was with him the whole time and said that he didnt smoke marijuana ….. i am worried and dont know what the cause could be, iam assuming that he didnt get enough sleep in the past few days……
    note: he drank 3 energy drinks in one day(the day he was hallucinating ) i dont know if that can cause anything …..
    Also my 2nd brother told me that he got in a fight with him , not a physical but an argument i guess, i dont know if that could’ve trigered anything. i mean we had many biger arguments with him but never resulted in him hallucinating or even going crazy.
    right now he is carzy to me ,because most of what he says does not make since. if i ask him what time it is he might reply then he would say something like what time the flight will leave, and then say he took the wrong way he should’ve took i95… i have never seen him in that state before , normally he talks about the same things over and over such as people trying to kill him and demons and ghosts
    i dont know what to do,will he be back to the way he was ? …..PLEASE HELP , ANYONE

    1. Please write to me NOW. My brother has the same case as yours and he has ALSO been smoking and abused it. We have took him to the doctor and he feels like people are going to kill him too. Please write back to me at angel_solo123ab it’s my yah00 account.

  12. Hi, im 17 and from the UK,
    I have found this article extremley intresting and well wrote.
    i went through 2 years of non stop smoking of weed, i dont see that much of a problem. I originally started smoking weed to help with my moderate depression. I do believe weed is linked to Depression and Anxiety but i think every stoner knows this.
    I would like to mention a point that was made about super skunk. Alot of what was in the 70s and 80s i think i would of loved it, but now adays THC levels are sky high, and not in a good sense, studys show similar effects of UK cannabis as LSD.
    So ive stopped smoking weed for that reason alone. I want to smoke nice hash/pot Just proper grows in the ground weed. Not some Mutated shit!
    The only link i can see is this super strain weed!!
    I recently ended up in hospital after one spliff, My pupils were wide, i was throwing up and couldnt move. Later to find the weed had been sprayed.
    Its all thats on the street at the moment and i bet it is in USA and everywhere, people saying “this is the strong good stuf” fuck that i just want some nice easy smoke?
    If this new strains have same links as LSD no wonder everyone fells a bit fecked in the head haha. But do remeber, we all are a bit loopy in our own sense, we all have our problems… its what makes us different.
    Just cause they flare up during ur smoke dont mean its the smoke =]
    Peace and love guys, would love to hear you feed back =]

  13. Hey guys- I really enjoyed this article, and in reading me it has allowed me to be in sort of a better state. Im 15 and started smoking pot about 4 months ago.. first time, nothing… but then i went to a friends and used a “Gravity bong” with hash, and thats when my Suspicions came on… I was seeing things that weren’t their, hearing a re-occurring voice saying things as simple as “Light switch”, became very paranoid, and actually hit a friend cause I though he was part of a government hierarchy that knows about aliens and what-not. Since then I have smoked regularly, and now, after almost 5 months, I have started having calm, cool, relaxing, and very “sorting” times. I feel although thoughts when I’m sober are now less blurry, and my school marks are going up.
    I feel better throughout my days , and can think clearly. These “Schizo” symptoms (And I hate to say that) Seem to be my anger sorting itself ina sort of “De-fragging” type of format. My great depression, in which I would go to the extent of self harm and extreme suicidal thoughts are now completely abolished. My creativity when playing guitar has greatly gone up too.
    Sorry it was so long folks. I just wanted give you MY full experience so far.
    Have a good one. 😉
    Au revoir.

  14. Hi, I just wanted to tell my experience this month. My friend Jessica, 24 years old, just recently started smoking weed everyday of her life. It’s been about a year I’d say since she started doing it like this. back in her high school day’s she smoked every so often, nothing like she was now. 2 weeks ago she started acting strange in a way I’ve never seen her act. She started staring off into space for long periods of time like she was thinking really hard about something. And then it just kept getting worse. She started asking if she was going crazy and I told her “No you’re not, you’re just thinking too hard about things.” . Within the next day or 2 after this I was woke up by her saying she was going to go to the police station to report a man for raping her. We questioned her about it and she couldn’t give us a straight story. She kept changing who it was and where it happened. She even started saying she raped someone. She just kept coming up with crazy stories! She said once, ” He told me that if I hurt him he would give me schizophrenia.” She is now in the mental home being examined to find a reason why this happened. She still hasn’t gotten much better. When her mother and boyfriend came to see her yesterday she said to them “I didn’t think you would come because I thought I killed you.” I don’t know what caused this but it does seem strange to me that she just started using marijuana everyday before this happened. I placing my opinions on seeing something like this happen Humans are all the same, me, you and everyone around. We look for the good things in the things we like and the bad in the things we don’t. People who love to smoke weed will go out of their way to find proof on ways it helps in research and completely deny the ways it can hurt, vice versa, people who despise weed will do the opposite. If you don’t believe it, how many of you have had a girlfriend or boyfriend who you really liked and heard many people say how bad they were in ways yet you completely ignored what you heard about them. I know I have, because I liked them. And how many of you have been hurt by that person exactly like someone told you they would. It’s life.

      1. I’ve been living with schizophrenia for 3 years now, and I have heard all the talk that Cannabis can worsen your schizophrenia, even after hearing all that, I decided to try using it moderately from a vaporizer, and it seems to actually be helping me a lot, My grades went up from C’s to A’s, I dont have my daily hallucinations anymore, and i seem to be functioning pretty well. Do you know why that is?

  15. Hey Robert,
    I had my first spliff at 15 years old, but didn’t start smoking regularly until 17; I am 19 at the moment. A few weeks ago, I had a severe panic attack after lighting up, triggered by the thought that I could become schizophrenic. I had been learning about the condition recently in Psychology, and suddenly it occurred to me that I possessed several risk factors for the condition – not least the weed dependency.
    I have been assessed by an Early Intervention Team for Psychosis, and they concluded that I was not at risk and have simply referred me to a cognitive-behavioural therapist for anxiety. However, I cannot shake the worry that one day, the condition will develop, and my sanity will be lost. It is comforting in the face of emerging evidence to see articles such as this, but I don’t think it’s possible for me to be completely reassured.
    To be honest, I never got that paranoid on weed – I got anxious towards the end, but only about the physical symptoms (increased heart rate etc.) If I were truly predisposed to schizophrenia, would its effects have come out when I was smoking? I may not be ‘schizotypal’ at the moment, but is my personality liable to change?
    I hope you can offer some insight

  16. hi robert,
    they say it changes gene expression, i do know this can be temporay and after abstinence genes normalise but sometimes genes dont normalise, somtimes this is permanent also this permanent change i think is associated when smoking in early adolescence, what do you know about this, i smoked from 19 regularly for about 1 and a half years and stoped as it made me a bit panicky. surely permanent gene expression change is rare?

  17. I find it odd that teenagers (some of the posters here, not all) think that they have more experience, more information, and more ability to diagnose problems. I think that perhaps we should all refrain from making diagnoses until we have gone through college and medical school and have our psychiatric degrees. Who do some of you kids think you are to have had one experience, and therefore paint all of reality, and other’s experiences with this tarred brush?
    THC can cause anxiety, I can get behind that – personal experience tells me that it would be foolish to attempt to deny this. I find that I agree with Mr. Lindsay in his assessment that THC can exacerbate pre-existing symptoms and conditions that would lead to schizophrenia, but not to actually cause the problem.
    Studies that have been done in the last decade – which has been difficult as the federal government (of the US) bans research into marijuana except for certain universities. I find it difficult to believe that after President Nixon or Reagan buried an impartial report made on the long term effects of THC and marijuana, that any report the government currently supports is entirely factual.
    The studies that have been buried showed definitively that THC does NOT cause lung cancer (when it is the only thing smoked), that THC does NOT cause psychosis in anyone who did not already exhibit the symptoms, and that THC is NOT physically addictive. Anyone who tells you that that last statement is false has no idea what the the difference between physical addiction and mental addiction is. Physical addiction is a situation in which a chemical that one ingests (or smokes, shoots up, drips on their skin, whatever) REPLACES a chemical that the body reproduces naturally, or it blocks the receptor for that natural chemical inside the body. Mental addiction is when a person ENJOYS being high, and DOES NOT WANT TO STOP. Anyone who tells you that “they couldn’t stop smoking pot” is full of it. They didn’t WANT to stop smoking pot – they enjoyed the high, or the cessation of emotional responses, or the change in those responses. THOSE things are what people who smoke pot get addicted to, not some physical/chemical component of the drug.
    On the topic of age restrictions – persons with undeveloped brains, whether due to incomplete growth, or some other underlying issue, should NEVER take ANY mind altering substance. I don’t care if it is recreational or prescribed – by definition, a mind altering drug ALTERS the mind – the chemistry, the physical composition or what have you. This is simple logic, and is really irrefutable – even from a medical standpoint. Anti-depressants are more likely than THC to cause schizophrenia, and yet people still pop those like they are Pez. All of the drugs you see advertised on tv have to have a longer segment of the advert detailing the possible side-effects than they do a segment detailing the benefits of taking this drug – and STILL people go out and buy those drugs – even when the side effects include DEATH, or a symptom similar or the same as what it is you are trying to alleviate. Pot doesn’t have those side effects (on healthy individuals), sorry but it doesn’t. The amount of THC that a person would have to ingest in order to take a lethal does of it is not possible for your everyday average smoker – the equivalent is somewhere near 900 joints in order to overdose on THC. The THC that had been smoked at the beginning of any experiment attempting this would have been distributed and neutralized by the body before you could smoke all 900 joints. There exists no true distillation process to concentrate the amount of THC you would need to hurt yourself with marijuana. All that being said, there SHOULD be age restrictions on things like marijuana, alcohol, prescribed drugs, etc. And teenagers should pull their heads out of their butts long enough to realize that they know NOTHING about their own bodies and what is going on inside them. No matter how many “health classes” you take, you are not getting accurate information – medically accurate that is. Your mind and body will be adversely effected to a MUCH greater degree than an adult whose brain, body and mind are finished developing. You have no idea the changes you are going through from the inside.
    To those people “who have brothers (or sisters/mothers/fathers/aunts/uncles/cousins) who smoked pot, and they went crazy,” you still have very little idea of what you are talking about – you personally do not understand the things that are going on inside your relations’s body/mind, and their doctor does. Major problem with that though? Is that doctors (in general) are dead set against any remedy that did not come from one of the test tubes of the pharmaceutical companies that send them perks, and pay them more money to prescribe their drugs. Natural remedies are to be feared, because with medical science, we certainly know more about how to fix problems with nature than nature itself does, right?
    Long story short: if you are under the age of 21, quite possibly, you shouldn’t drink alcohol, or smoke pot, or take too many “anti-depressants” (most of which have suicide warnings, did you know?). You shouldn’t do these things because you can’t handle them, but because your BODY can’t handle them – it is still developing, and no one knows for sure what long term effects doing these things will have on your overall health.

    1. Thanks for weighing in Cherokee, school money wasn’t waisted on you. I found your comments to be fact based , complete , and up to date including the modern medical approach to child phycology problems. No drugs are ok for a developing mind period.

  18. It’s the whole question of trigger or cause and my current dissertation concerns the review of literature regarding this matter. I am currently in the belief that there are individuals that develop the disorder regardless of exposure to cannabis or dysregulation of a related endogenous cannabinoid system, however exposure to cannabis later on in adolescence appears to trigger the disorder due to the effects laiden on by brain abnomalities. These include both the hippocampus and amygdala. So I’m thinking that certain people may have genotypes that make them vulnerable to exposure and the effects of cannabis and that cannabis causes a series of brain abnormalities leading to the disease, but whether or not you see that as the cause or trigger of it is down to opinion.

  19. My first drink was at age 14, and I would binge drink frequently until age 15, when I started smoking cannabis instead. I started blazing heavily and daily at age 16, and I am now nearly 23 years old. There are quite a few incidences of schizophrenia and other mental illnesses on both sides of my family, going back generations. I was diagnosed as having inattentive ADHD at age 17, and later, a co-morbid anxiety disorder that directly affected my concentration. Because of my family history I am highly vulnerable to developing schizophrenia myself, but I am not sure how much my cannabis use has impacted my over all chances. Then again, I may already be in the prodrome stage, and the THC may be making things much worse.
    I have felt that I was “different” since childhood, and even told that by some well meaning adults; its not as though I believe I have magic powers or secret knowledge, but like I was born decades ahead of an era I should have lived in (because of my “odd”interests and appreciation for history/culture/literature/philosophy I feel out of place with most people my age who really don’t give a shit about such pursuits.) Also, around age five I began seeing “shadow people” nightly, and not just out of the corner of my eye, but but right in front of me, which was terrifying. This continued sporadically for years. Sometimes I would be haunted by those wraiths for weeks in a row, then it would stop for months, even for a few years. Around age 14 it reached its peak. At this age telling yourself over and over again that you have an overactive imagination isn’t going to make these things go away. Interestingly, when I started using cannabis regularly, I stopped seeing them much less, and when I did, I would either ignore them because I could just chalk it up to being high, or I would confront them or try to communicate, just for shits and giggles. This effectively put an end to seeing shadow people regularly. In fact its been a few years since I’ve seen one, or at least bothered to notice them sneaking around corners or standing in doorways. Also, as I got older and started experimenting with hallucinogens like LSD, mushrooms, salvia, etc., I noticed that I “felt more normal” under their influence then I did when I was cold sober. Some people with schizophrenia often react with less confusion and are said to be more tolerant of the effects of psychedelics because they are used to the altered states induced by their disorder.
    When I started using cannabis, and later other drugs, I was going through a rough time in high school (who didn’t at age 15?) I didn’t have a role really other than the smart kid who would let you copy his homework, so becoming “a head” was at least a place for me on the HS totem pole, as sad as that is. I had strong social anxiety at this time, and I had delusions, which I recognized as such now and back then, where I thought people at the mall were talking about me. This all changed when I started smoking weed. I came out of my shell, started getting girls, and was pretty well liked among everyone.
    I developed what is called a dependency on cannabis, which I call “a reliance on weed.” Today I smoke infrequently, but the urge to do so is so strong sometimes, that I have stolen money to obtain cannabis. This is always precipitated by a sense that I am going to die if I don’t do “something” to get away from the feeling of impeding doom/insanity; either take a drug or drink, spend lots of money, have sex, go hiking when I need to be at work, etc. This sound like bipolar disorder, but I don’t believe it is. I am usually balanced in mood, but I have had brief manic and depressive episodes, usually lasting no more than four days total. The panic attacks come on totally randomly and with no easily defined triggering event.
    Lately I feel like I am be edging closer to full blown schizophrenia every day. I have stopped using marijuana regularly and all other drugs with the exception of kava kava. Luckily I have not had any visual or aural hallucinations. Acupuncture is helping me out greatly, but still I feel like I’m losing my grip on reality and will eventually lose it all together. Maybe its just stress and this will all subside once things in my life get a little more consistent, like getting a job I can hold without worrying about panic attacks.
    What I would like to get across is that in my research on this topic of a correlation between schizophrenia and cannabis use, the studies generally only mentioned cannabis as the drug being used EXCLUSIVELY by those being studied. I well tell you one thing I know for sure: ONE YEAR OF NEAR- WEEKLY DXM ABUSE (cough syrup ingredient) did 20x more damage to my brain and overall quality of life than 8 years of smoking cannabis has. If I had not abused DXM I feel my life would be so different. Had I only smoked weed growing up I feel my life would be much better now.
    After high school I flunked out of college because I became so depressed and ill. This was after ceasing all DXM use too. Today I still live at home and suffer daily because of my anxiety, lack of motivation, feelings of hopelessness, and stress keeping me from finding and holding a job. I finally decided that I want to become an acupuncturist, and will go back to school to pursue this career path. Cannabis has not really helped me in coping with life, in fact it probably really has made things a lot worse for me. If I could do it all over I would have waited to experiment with drugs until I was at least seventeen, probably later. Most people don’t and won’t ever have a problem with it, and clearly cannabis use/abuse does an iota of a fraction of the damage alcohol abuse does to our society. But in my case, I developed a reliance on cannabis to help cope with my mental health issues, which ultimately has held me back in life.

  20. Hello, thank you so much for this article it really helped me. My father suffers from scitzofrenia and I have always been worried I will get this illness. The fact that pot use and scitz are linked scares me a lot, because I feel as though I am already prone to it. Everytime I reasearch ways to try and prevent getting szitzofrenia it always says to stay far away from pot. I will do so if I have to, I am not a heavy user but I still enjoy it once in a while with friends. Will useing cannabis even after age 21 still trigger scitz in people who will develope it anyways?

      1. After age 21 your risk is all used up, from cannabis anyway.
        Cannabis won’t cause your schizophrenia. It will just bring it on sooner and make it worse if you are going to get it anyway, that’s all.
        How old are you?

        1. 17. I think I will hold off until my risks are gone. I was just worried that even if I wasen’t going to get scitzo, the cannabis would trigger it to start no matter how old I am. Thats what almost every medical paper I have read says and it bothers me a lot. Thank you for your help.

    1. Hi E.D.
      Please read what I wrote just below your post.
      My son has schizophrenia and used marijuana before the onset of schizophrenia. It is such a scary illness, please be safe and don’t use it,
      it’s not worth it.
      I really don’t believe the nonsense that it won’t cause you harm if you use it only after 21. Even if you don’t develop schizophrenia, think about your life and the ability to get and keep a job if you are a frequent user.
      You don’t need it to feel good.
      Just a mothers advice …just don’t do it.
      Hope all works out well for you E.D.

  21. Hello,
    I am a mother of a 20 year old son who has schizophrenia.
    He started smoking marijuana at around 16 and his personality completely changed. We were so close before and then I was his worst enemy for 3 years. When he was 18 he begged me for help because he was hearing voices. He was also behaving bizarrly. He wouldn’t accept any help and continued using weed. Eventually I had to put him out because he was becoming very violent and thought I was out to get him.
    To make a long story short he ended up in another state and got in trouble and spent time in jail and in a psyche hospital where he was diagnosed with schizophrenia. He was on probation for 1 year and he had to be regularly drug tested. He used no marijuana during this time and is on medication.
    for his illness. For the first time in 4 years I feel I have my son back…he is loving and thoughtful again…he definately has schizophrenia but is coping so much better since he is on medication and not using weed. He talks about the time he first felt psychosis…..he feels it was from some ‘bad’ weed right after he smoked it. It must have been very traumatic for him, even now he cannot go to sleep without the lights on.
    He is not on probation anymore and he hangs around people who smoke weed, I am very worried that he may start smoking again. I pray that he does not do so because I know that no good can come of that!
    I want to appeal to especially young people who smoke weed or are thinking about it ….Please don’t try it.
    Even if only about 1% of the population develops schizophrenia, and marijuana likely helps in bringing on the onset of those already at risk . It is still too much of a risk!
    It may not happen to you but it may happen to your friend that you encouraged to smoke it. My son started to smoke because of peer pressure.
    I have never smoked, used alcohol or drugs so I don’t know what it is you ‘feel’ when you’re high. But what I do know is I have seen a lot of lives destroyed because of marijuana use ….people unable to get through the day without it …not being able to keep a job…stealing to support the habit… and
    being high so much of the time.
    I have seen what it has done to my own son and even if he did not develop schizophrenia I would wish he wouldn’t use it either.
    Young people there is so much more to life than getting ‘high’ . Be strong, you don’t have to give in to peer pressure.
    As far as I see it, Peer pressure is when some feel they need others to do the
    same things they are doing (and it is always something that is not good for them) so they won’t look as bad as ‘everyone’ is doing it!
    When did someone pressure you into doing something good? Never , Right?
    If someone is pressuring you into doing something your ‘gut’ is telling you could be bad for you, just don’t do it. There are others out there are doing good and getting ahead in their lives you Don’t need friends that lead you down the wrong path!
    I don’t believe you are missing anything good by not using marijuana,
    in fact you are doing your body good by not doing so.
    This last note is for Robert.
    I do believe the theory that marijuana use is definately bad for those predisposed to schizophrenia which you stated in your article. And it may not cause schizophrenia to those not predisposed.
    What I object to is your telling people that after 21 it is safe to use it.
    People are better off without ever using it, try to steer kids away from it rather than to it.
    As for marijuana for medicinal purposes, I am not sure I object to that but
    just for recreation, I believe one would be better off never using it .
    Thanks for hearing

    1. My brother has schizophrenia, he used to smoke weed, i dont know how much and i dont know when he started but i do know that his schizophrenia didnt develop UNTIL HE WAS 23

    2. Thanks lisa for weighing in again. your use the words kids to refer to adults. first of all no one ever stole to support a weed habit. i’m not sure you understand that a persons ability to get a job or keep a job is fact based. I feel bad about the problems your son went thru as a result of his weed use. but is there a posisibilty that there were other drugs. Your son is a man and he didn’t need your tight relationship after a certain age. Also I think you should try some weed it will help you understand and let your son move out and start his life without your monitoring. I think you’ll find out there were other drugs affecting your motherly bond with him.

  22. Lisa im sorry your son developed schizophrenia. But you cant point blankly black and whitely blame cannabis for this. I myself am autistic which causes me great difficulty interacting with people and great anxiety depression of going to uni. However i smoke cannabis i guess maybe 1 joint a week at most. I believe it has given me a great understanding of existence overall and not the fake reality we live in, where its not who your are as a person but how much better you are than other people… What im trying to say again is im sorry your son developed problems but their are so many issues in life that cause problems that it simply childish to point the blame at one thing. What im saying is the main joy in life is to try everything, my favourite quote is we try and make it safely to death. What im saying is that life isnt the perfect place where everythings happy and perfect. Its about just trying to enjoy it in a intelligent manor. Lastly im sorry if ive made you feel bad in any way, i just think you can tell people what to do, i understand its from loving protective place but people have to live their lives and make mistakes

  23. I as writing and it got sent, I’ll continue here
    My brother has schizophrenia, he used to smoke weed, i dont know how much and i dont know when he started but i do know that his schizophrenia didnt develop UNTIL HE WAS 23 so telling people it’s ok to start smoking after 19 is not only a lie but a very irresponsible thing to do, I know the author of the article did it with the best intention and truly believes what he writes but he doesnt know what schizophrenia really is, it’s a living hell for the person who has it and for the people who love that person.
    To be honest i found this article while researching this topic because I’ve smoked pot a few times a while ago and I was about to get some more to smokeonce in a while..but honestly even after reading this article, even if all you say is actually true which I doubt, I dont think I could take that risk…I dont want to expose myself to that hell even if it is a remote chance, I couldnt do that to me or my family.
    Lisa, you’re probably not gonna read this but if I were you I’d do everything I can to keep my son away from his pot smoking friends, they’re probably great guys (I have absolutely nothing against pot smokers) but if he hangs out with thm He’ll probably start smoking again, then He’ll try to drop his medication and He will go back to a psychiatric hospital (All this will happen too if he drops his medication even if he doesnt start smokng again, but I’m sure yu know tat. His medication is VITAL)

    1. The studies are quite clear. Even the studies implicating pot and schizophrenia find that your risk is all used up by age 21. So there’s no risk if you wait until 21 to start, and little risk if you start at age 20.
      Anyway, the best analyses show that pot doesn’t cause schizophrenia at all. All it does is bring it on sooner and make the symptoms worse. The rate is schizophrenia has been flat to declining from 1965-present. The rate of pot use has gone up by at least 40X. If pot was causing any schizophrenia cases at all, the schizophrenia rate should have gone through the roof.
      Pot didn’t cause your brother’s schizophrenia. That’s all there is to it.

      1. I know it didnt, ltough I’d love to know what would have happened with him if he hadnt smoked at all…I think he would have had itanyway, or maybe not seeing as he developed it at 23 which is really late, maybe if he hadnt been using drugs h wouldnt have developed it, I’ll never know.
        I agree that pot doesnt CAUSE schizophrenia, however I do believe that if a person has the genes for it and He/She doesnt smoke he or she might escape it.
        I’m 18.

        1. Wait until you’re 21 if you’re going to use pot, Nick. It’s in your family, come on.
          Actually, your brother may have developed it later on, like 27 or so.

        2. See, that’s contradictory. You say that pot doesnt cause schizophreniait just makes it appear sooner and you’re also telling me that i could smoke weed after I’m 21.
          So basically following your line of thought you’re telling me that I will have schizophrenia eventually which is pretty stupid because it’s very rare to have two cases in the same family, or you’re telling me that smoking weed right now will cause me to develop the dissease whcih contradicts what you’ve been saying up until now.
          I repeat, i have nothing against weed or you, and I’m not sure that it causes or doesnt cause schizophrenia. I’m just trying to figure out the logic behind your line of thought and your advice to smoke weed freely after 21 regardless anything.
          And actually, i’ve heard about a lot of people with this dissease and i dont remember any case that started as an adult, it’s always during the adolescence or the early twenties

          1. There is some sort of a triggering risk apparently. If you want to avoid that risk, wait until you’re 21. It’s not at all very rare to have two cases in the same family. The risk to siblings is quite high. My risk is 1%. Yours is much greater than that.
            Many cases start as adults. We even have cases starting after age 45, believe it or not.

        3. So basically the conclusion here is marijuana doesnt necessarilly cause schizophrenia but it could, and this risk is much higher when you have a history of mental illness in the family.
          It’s a very interesting and disturbing topic, this one. I’m from Argentina and right now they’re starting to debate whether or not using and selliing pot should be legal…I really dont have my mind made up yet, I really dont know what to think.

        4. I forgot.
          Dont you see the contradiction between this:
          . If you want to avoid that risk, wait until you’re 21
          and this:
          Many cases start as adults. We even have cases starting after age 45, believe it or not.
          I mean, if my schizophrenia could appear at any time and my risk is higher because of my brother’s case, why would it be safe to smoke weed when I’m 21?

    2. Hi Nico,
      Yes I did read your posts. You seem quite mature for 18 and you are wise to be concerned about the effect marijuana could have on you.
      We both have a loved one with schizophrenia and see the terrible devastation it has on them and all who love them.
      I am not at all saying that my son’s schizophrenia was caused by the marijuana but I know for sure it triggered it along and definately makes it worse for him when he does smoke.
      I know how my son was before he smoked ….he was a joy to be around.
      While smoking and developing schizophrenia I was so afraid of him. He admitted to me he was a very heavy smoker. And when he was on probation and off of marijuana he was good to be around.
      Just from the experience of seeing my son while using weed and not using there is such a big difference. I know for sure people with schizophrenia or with a family history of it should stay far away from marijuana.
      Please Nico, follow your gut feeling and don’t use it even after ’21’.
      As for people who don’t think schizophrenia could happen to them….my son was one of those. I am sure it is just not worth the risk.
      All the best to you Nico…. thanks for hearing.

  24. Because, Nico, studies have found that the triggering effect is all used up by age 21. In a young person, the brain is still developing. Cannabis may interfere with this development in some way to trigger schizophrenia. By age 21, you can use it all you want, and whatever else it will do, it won’t effect your schizophrenia risk. I’d frankly advise you to wait a bit if you want to use it.
    Also, by age 20, most of your risk is used up. You’ve only got a little elevated risk.

    1. I’m glad I found this article and had this little debate, as I’ve said before i was about to buy an once to smoke just once in a while, I never intended to be a heavy smoker, I think that mental illnesses aside nothing good can come from that. I’m not gonna buy anything now.
      I wish more people knew all these stuff, look at me my own brother has schizophrenia and I was about to do something that could possibly ruin my life and ruin even more my family’s. As me there must be a lot of people that doesnt know all this or doesnt think that they could ever have this dissease, as Lisa said, it’s not worth the risk…this is probably after death the last thing you would want for you or for a loved one.
      Lisa, best of luck for you and your family I hope everything works out for you.

      1. Thanks Nico,
        I believe you have a great future ahead of you. You have thought this out carefully and come to the best decision. Your family can be very proud of you.
        Stay strong.

      2. I am afraid that at age 18 you are still at the age where the cannabis-schizophrenia mystery plays out. If you are worried about schizophrenia, I do not feel you should use cannabis at this time. If you wait until you are 21 though to start using, you at least won’t have to worry about any cannabis-schizophrenia issues. Even by 20, most of your risk is used up. But at 18, you are still at the risk age.

        1. Hi Robert,
          Your article was very interesting, I have a very personal experience with schizophrenia and I do not know the role marijuana had to play in it. I have been a pot user since I was about 22. My wife was a cigarette smoker since age 18 and alcohol user since 20. She started smoking pot since age 24 – sometimes 3-4 times a week sometimes once daily. Around the age of 29 she started developing symptoms of schizophrenia, which was full blown by the time she was 30 (with auditory hallucinations). She has been in treatment for the last nine years. In the opinion of her psychiatrist, it was the use of pot that triggered and maybe even possibly caused the illness. Reading your article and your responses, I am now confused whether this is possible as you have said that the safe age to start on pot is 21. Would love to hear your thoughts on this.

  25. Ok I’m 18 and I’ve been smoking pot since I was 14 and I’ve never had the thought of schizophrenia until my dad told me that my grandfather had it from smoking weed but not just regular weed it was laced, on top of that I think he was doing other drugs and the same goes for my dad tries to influence me to stop smoking by telling me the same story how schizophrenia runs in the family and I’m starting to become convinced but then each time he tells me the same story he exaggerates it even more to try to scare me .it sounds plain and obvious that schizophrenia is not in our genes and my grandfather and uncle just bullshitted and smoked the wrong main point is that I’m getting ready to leave for the army in 3 and half months and I want to enjoy my most favorite plant before I leave so do you think what my dad has been telling me could happen to me in such little time if ive been smoking for this long without a trace of schizophrenia?………. plus I have control of what I smoke so I make sure its not laced with anything . Someone let me know ASAP before I quit smoking early and for the rest of my life

      1. Hi Robert,
        I have read your article and do agree with you that marijuana does not cause schizophrenia! You have also addresed the fact that marijuana use in people predisposed to schizophrenia (family history etc) can bring on schizophrenia.
        I have looked at other studies that show that if a person predisposed to schizophrenia does not use marijuana the chances of developing the illness is less than if they used.
        I truely believe that my son may not have developed schizophrenia if he had not used marijuana.
        What I am trying to say is, wouldn’t it be better if we tried to keep young people away from marijuana?
        What does it profit you to tell them it is ok to use marijuana?
        I have friends that use marijuana, its not that I am trying to be holier than thou but without the peer pressure that my son felt and his decision to use marijuana it was a big mistake which I would not wish anyone to bear.
        Kids are not mature enough to handle marijuana…..lets try to steer young people away from it. Just because you enjoy it and you say it has not adversly affected you is no reason to give them the green light to marijuana use.
        Thanks for hearing

        1. I haven’t used cannabis in about 2 years now. I’m actually quite concerned about it myself. The research on cannabis and schizophrenia is very disturbing, but it’s not conclusive at all. I think at worst it brings it on up to several years sooner. The main thing is that the rate of schizophrenia has not gone up while the rate of cannabis use has gone through the ceiling, literally exploded. It just doesn’t make any kind of sense at all.
          I’ve looked at all the studies and it’s true that they keep finding a relationship. OTOH, the rate has not gone up even 1%. It’s been flat or it’s even gone down.
          Nevertheless, just to be on the safe side, I do tell people that if they wait until they are 21, they are in the clear as far as cannabis and schizophrenia. The relationship between cannabis and schizophrenia disappears at age 21. There are also concerns about cannabis and brain damage. I have a lot of worries about cannabis that I did not use to have.

    1. Hi Cliff,
      You are quite right to be thinking about your marijuana use and schizophrenia.
      You can read what I wrote about my son (20) who has schizophrenia and he used marijuana heavily from around age 16. Robert may be right that by itself, marijuana does not cause schizophrenia. If you have a close family connection with this illness your chances go up tremendously by using….much higher than the general populations 1%.
      Your father is very worried about you developing this ilness because he loves you and wouldn’t want you to ever have to go through this very traumatic, debilitating and scary lifelong illness.
      You may never develop schizophrenia but it’s not worth chancing.
      Do some more research and think hard about it. Here is a site I found interesting.
      Good Luck Cliff

      1. Robert, thank you for your explanation .
        I am glad you clarrified your position to me.
        Schizophrenia is such a horrible illness and if we can
        help even one person lessen their chance of developing it ,
        that is a good thing.

  26. hey rob
    i suffer from anxiety and emotional pain and i was wondering if smoking pot every now and then would help cure it

  27. *paranoid schizophernia*
    hi my name is ANURAG. I have live in INDIA(MAHARASHTRA) NANDED.
    please help my email id-**
    i have exercise daily,i have great body but brother it was started from june 2011
    i can not receive calls or make any calls to anyone i hear my voices from my calls and i fearing.
    I think peoples around me at college , bus-stops,raily station, they know what i have thinking bcoz all eyes on me.
    when i alone in my home while i have studying
    i hear my voices outside home very loud,and if television or radio is on neighbours home i think people on television or radio are broadcasting my thoughts to other people.
    i can not studying now from june 2o11.i can not going to college exam.i think i have no future .
    i can not going outside home,festivals,marrages,party,but i have go sometime when i have bike without bike i have not do anything outside,bcoz i think people are know where i gone,my ways,and they judging me. so i could not speak them i only see their face and think i have fight or i have great body not fear it just paranoid.
    but with great body i have also fearing .
    i have lot of fears to do something,to go outside home,i have listing musics all day to calm my thoughts,unable to studying,
    I love to listen paranoid from weed song nane Only God Can Judge Me & All Eyes On Me&Fear Of Death&Me Against The World-Tupac Shakur
    i think i have alone with this problem..plz help me

  28. I’m a final year psych student, and while I appreciate reading a pro-drug article that takes the time to consider genuine empirical research, I do have some issues with your article and the comments below it. The main issue stems from both the writer and commenters having very black and white viewpoints about a pretty grey area. Saying cannabis does/does not cause schizophrenia, implies that there is one single illness called schizophrenia that can have causes and cures, which is not necessarily the case. Schizophrenia, like all mental illnesses is a convenient label to facilitate treatment methods and medical communication, but if you consider that the symptoms defined by DSM-IV are pretty broad, it is more a definition for a spectrum of perhaps seperate disorders.
    If one agrees that heavy cannabis use can make one a bit lethargic, perhaps lose your train of thought quite a bit, have some memory issues, and experience a degree of depersonalisation or paranoia, these are all common symptoms of various types of schizophrenia. I would also warn against trusting the comments under this article about any areas of neurochemistry, since this a tricky area. Saying that one drug affects a neurotransmitter and another drug does or doesn’t, means nothing without specifying whether it affects reuptake, metabolism, release, blocking etc. and exactly where this occurs in the brain. Read Tan, Lauzon et al (2011) to see how complex this area is.
    I sympathise with the author complaining about ridiculous statements in the media saying that 14% of cannabis smokers will get these effects, which generally are pretty shady. However, for someone who complains about the narrow mindedness of researchers in looking at cannabis, you can be equally narrow minded. You refer to “cannabis” several times, when talking about its effects and potency, at one point calling it a “meager” drug. What “cannabis” is this? Weed? Hashish? Bubble hash? Hydroponic skunk? White widow? Are these all the same? The Dutch are reversing their policy on cannabis not because of a bit of “waccy baccy” but because of hardcore strains that can be severely psychologically damaging. Cannabis itself is a drug that also doesn’t exist in any one form, with specified potency etc. , so this argument is a bit pointless.
    Final point: to all the idiots who are saying cannabis doesn’t cause cancer. Smoking oak leaves would give you cancer. Smoking oregano would give you similar health issues. Its got nothing to do with the drug, its about inhaling the burning plant matter, and subsequent Carbon Monoxide.
    Long post… interesting debate though.

  29. “There is also evidence that cannabis is protective against the neurotoxic effects of stroke and head injury. Further evidence shows that cannabis is effective in slowing the progression of various neurodegenerative diseases such as Alzheimer’s, MS, Parkinson’s, and ALS (Lou Gehrig’s Disease).”
    This could be an indication of less in glutamate receptor stimulation. Ly2140023 trials are currently being done and being referred to as a 3rd generation anti-psychotic. Ly2140023 stimulates glutamate receptors and have been shown to reduce psychotic symptoms in schizophrenia. Ly2140023 does does not rely on the dopamine theory and instead relies on the theory that less glutamate stimulation increases psychotic symptoms. The above quote is an indication of less glutamate stimulation which is scientifically related to psychosis. Admittedly it is an indirect measurement but to date measuring imbalances of chemicals such as dopamine and glutamate in the brain are not practical and until we can have a more accurate view of the actual imbalances in the brain it is hard to say what will cause and cure long term psychosis. However, the above quote would indirectly indicate a lasting effect on glutamate stimulation being lessened which could increase psychotic symptoms as opposing drugs such as ly2140023 lessen them in diagnosed schizophrenics that have been drug abuse free for at least 6 months. This could be an indication of less in glutamate receptor stimulation. Ly2140023 trials are currently being done and being referred to as a 3rd generation anti-psychotic. Ly2140023 stimulates glutamate receptors and have been shown to reduce psychotic symptoms in schizophrenia and is a method that just may be the way for the 3rd generation anti-psychotics. El Dopa also helps those in the above quotes too, however can also cause psychosis in prone individuals.

  30. I am a living testimony as to why marijuana is harmful. I started smoking marijuana when i was 17. When I turned 18 i smoked the most i ever did and I started to trip really bad I thought that I went to hell in the dangerous streets of Liberty City, Miami. I was hospitalized in the mental ward and given medication. After I was released I smoked on 3 different occasions, the first time I did it I tripped a little the second time nothing happened the third time I went “loco” and I was paranoid for about 3 weeks until I started to get comfortable with the medication. After that I got sent to the mental ward again they diagnosed me with paranoid schizophrenia and psychotic depression and psychosis. This is all a result of my use of marijuana at a young age, while my brain was still developing. My message is geared to all marijuana smokers. Marijuana is dangerous it can ruin lives, as a result of marijuana I am homeless and I have disease also I am now dependent on medication and probably will be for the rest of my life. I have lost the passion of life and I am lazy and I sleep too much because of this medication I must take in order to be normal as a result of marijuana usage. Please be careful, Much love everyone.

  31. MJ is tricky and there are many diffrent strains of the stuff. People do not react the same to MJ each time because of its diffrences in THC, and CBC and what these two chemicals do in a body is diffrent from person to person. The main way Cannabis is ruining lives is through what law enforcement has done locking people away for 20 years at a stretch or forcing someone to spend every last dollar they ever made to defend themselves makes for a terrible place to live. I read every single word and post on here and see a bit a trend everyone is paranoid about this drug. I believe that is mostly to do with the fact that everyone in their lives has heard some horror story or another about the plant. And I believe firmly that there is large barrier between what eveyone is told and what is true.
    schizophrenia is a terrible disease and is widely mis diagnosed and the symptoms are not clear or all the same from one indivdual to another.
    I have loved ones who have been diagnosed with schizophrenia which i feel doctors in mental health hospitals diagnose to often without talking to the paitent or taking time for a full diagnoses (it cannot be diagnosed in a 2 or 3 day stay in a mental health facility). Meaning finding out about a persons background including things such as diet, exercise, sex life, family life and other essential things that would be helpful. Many things like depression, ptsd, traumatic childhood events, and other traumatic life events can really mess with a persons head. And america’s mental health system is very very fecked up as is our legal system.
    @EJ one thing to note some strains of MJ gives boost of energy. while other strains will straight knock you down. Some people will have “special” stashes of weed laced with other drugs. it sounds like you smoked three diffrent strains and that last smoke just might of been laced it happens.
    now for a question have you been put on lithium or seroquel or any other strong psyco active drug?
    if so those particual drugs at such a young age could REALLY REALLY REALLY MESS YOU UP FOR LIFE. way worse than what you thought cannabis could. My advice would be to get triple and quadruple opions from doctors before you continue to use those. Another problem with schizophrenia is that caffiene is very bad for it and can cause more problems than you realize. If something is going really weird with a loved one the first thing you should look at is their diet. If they are injesting large amounts of caffiene or sugar there could be a reason for the outburst. such as three cans of redbull in a day with someone who is on prescription drugs for schizophrenia that much redbull and caffiene and sugar can neutralize alot of the effects of those drugs especially if the patient is on some kind of upper or downer for mood stabilazation.
    @ Lisa i’m sorry for you and what you have to go through please with all your might do more research into the drugs your son is taking. make sure to get your perscription filled at the same pharmacy. Those drugs he’s taking are harsher on the body than cannabis could ever be i promise you that much.
    @Robert good article

    1. Thank you my friend.
      This whole argument is just nuts. As cannabis use went through the roof over a 30-40 year period, the rate of schizophrenia was either flat or declined. There is no way on Earth that cannabis could possibly be causing schizophrenia in those circumstances. It makes no sense at all.

    2. Thanks…..I am researching everyday to try and help my son.
      He stopped taking his medication about 4 months ago and became very psychotic and paranoid and began smoking marijuana again ….he ended
      up in hospital and came out last week. I know medication is harsh but if you see
      him without it it is very sad. It is a nightmare for him, and me, to watch him having to go through this.
      I still am quite convinced though, that marijuana is no good for him

  32. Hmmmmm……
    Cocaine & its derivatives cause a form of schizophrenia. Meth too.
    Did my PhD dissertation on the effects of sidestream cannabis smoke.
    I’ve seen nothing convincing in the literature that any form of schizophrenia is caused by cannabis in any form or dosage.
    Temporary ‘paranoid’ sensations aren’t very unusual in some cannabis users.
    Keep in mind that the ‘psychoactive’ components of cannabis are very ‘lipophilic’ & partition GRADUALLY out of the nervous system over quite a long period of time. Days, weeks, months in some individuals.
    Having known some heavy long term cannabis users personally I can say there is something ‘odd’ about them. More like slowed mentation & a general ‘hazy’ affect.

  33. To start, reading this article was a blast! I’m 20 days short of my 18th birthday, and I first smoked weed when i was 13 or 14. I have always had violent tendencies (from a very young age) and often express anger in anything that I do. When I was 12, I was put on prozac for anxiety and depresion, and even taking large dosages of this medication I was never 100% happy. Currently, I am very confused about who I am and the state of my future. I am a smart kid, I’ve gotten straight A’s throughout high school and participate in many sports. However, I also have this dark side, if you will, in which I believe that everything is a concpiracy and at times I get so sick of the world that I wish it would burn, but I hate seeing people get hurt. See my problem? Whether I truly am messed up in the head, or I just have more hormones than most teenaged guys or I have a personality complex, I enjoy nothing more than smoking weed anywhere from once a week to several times a day for weeks on end. At times I do magic mushrooms and MDMA and cocaine, but I feel the negative effects of those drugs as soon as the high wears off and refrain from further use for a long period of time, often years (first time that I tried shrooms and MDMA was when I was 14). My question is, other drugs aside, should I continue to smoke weed? I have mental illness in my family and as I mentioned previously I have been on an anti-anxiety/depresion medication when I was only 12. Oh, I forgot to mention that I don’t drink alcohol.

  34. I am a 35 year old guy from Canada, who has smoked weed chronic since I first tried it at age 15. I have had Full on Schitzophrenia since i was 17….
    I was a high level Hockey player at the time, popular at school and experimenting with cannabis and mushrooms. I was injured with a serious concussion during a hockey game, got Knocked out anding pain felt goofy , had headaches and burning pain in my head. At the time concussions were not treated as seriously as now and i played the rest of the season , compounding my head injury….months later I went into a sudden psychosis, with terrifying hallucinations and voices. The doctors told mom I would be in an institution all my life. I was a vegetable….But my mom busted me out of the hospital and began to nurse me….and push me to fight this…..I lost a lot of friends but mom made me go to school and try to work and get better….eventually I did, and most of my symptoms are gone…..I graduated, found a careear and live independantly……All while smoking weed, which I find relieves the anxiety and depression…….pot is not a cure all, the medication and help of a doctor , as well as family support, and a positive stubborn attitude that , ” I Will Beat This”……good luck

  35. Now i smoked weed at 13 and became a everyday smoker from 17 to 20 from the time i woke up until the time i went to bed Now im 31 and cant even enjoy weed IT causes me a panic attack i feel like i cant breath I get extremely paranoid and think im dying or its the end of the world with schizo like stones that just made me give it up But every now and then i try it to see if i get the same outcome and i do wether it reg mid or nug I think the brain needs time to develop before they should use drugs Cant use coke either use to make me feel great socialable just great now it just makes me not want to be around anybody it is possible that weed can cause schizophrenia when used from a young age due to the brain still developing and everybody always says just weed thats it not going to do anything else oh you will it is a gateway drug thats the truth Im not against weed at all just speaking truth It does have medical benifits

  36. Im 20 years old and last sunday was the first time I got high. Me and my friends had brownies with marihuana I had 1 and half. At first everything was okay I juts laughed at things but then I became really really paranoid it seemed like everyone was talking bad about me and insulting me, and I was incapable of responding. Then I start seeing faces on the walls, and voices and wasnt sure if I was in the real life anymore. Im not planning on getting high anymore but can I develop schizophrenia after only one use of marihuana and a psicotic experience or is this common in first users?

  37. Pot made me schizo. Hell Yes! I only smoked occasionally when I was 15. I hated the experience every single time, but continued because my friends did it. Finally I went totally crazy. Had to stop. And for about 13 years my mind was very much f-ed up. I was so paranoid that I couldn’t wipe my ass after a shit. Scared someone poisoned the toilet paper! It was the worst time of my life. I’m better now–but the paranoia is still there a little. I can’t understand why people enjoy it. I hate the stuff. HATE IT!!!

  38. Say you’re nineteen and never had symptoms of schizophrenia, but both your mom and sibling have schizophrenia. You smoke pot occasionally. Are you at greater risk of developing schizophrenia or not? Let’s also add that you had been doing it for a while, and it had no negative effects, but actually seemed to help you function socially etc. Should this be a concern? Should the person stop smoking pot? There seem to be mixed reviews on here. I haven’t seen proof, but don’t want to take any chances.

  39. To everybody that has said marijuana leads to schizophrenia or psychotic thoughts, have you ever considered other factors that could have led to these things..?
    There is no evidence to suggest that cannabis does anything but good things, spiders on cannabis have produced very cool webs (haha) and in certain states of the US, marijuana is a prescribed drug. Would doctors really legalize a drug that can give you schizophrenia in this day and age? I think not.
    I’ve been smoking marijuana for about 4 months and I can honestly say it has made my life better. I wrote an essay whilst high, it had amazing description and I got an A. Marijuana makes you happy, calm, relaxed and whilst high you feel as if you have no worries and as if the world is a better place. I feel like I have Dysthymia, which is a mild form of depression, although this hasn’t been confirmed by a doctor, and weed makes it better. Marijuana is a prescribed drug as I mentioned earlier and one reason it is prescribed is to deal with depression, so I feel it has made a difference.
    Honestly, I agree with this article so much, and I do not see how these people that are arguing against it can say it is so bad, as the only people that think marijuana is bad are the ones who have never tried it. Period.
    There is evidence that many great people in history have used marijuana; Bob Marley, George Washington, Picasso, Queen Victoria, William Shakespeare, Charles Dickens. Should I go on or do you understand yet?
    As a final point I would like to state that the majority of you that have attacked this article, cannot actually spell, this leads me to believe that you are dumb, and therefore how is your opinion even relevant, as if you cannot even spell, how could you possibly understand a thing like this.
    I would advise everyone to try marijuana at least once, and then form an opinion about it. And I am in no way suggesting that people under the age of 16 do it, even under the age of 18, I agree with this article where you say that it should only really be done over the age of 18, and so I am going to prevent smoking weed until then, then I will wake and bake.

  40. Hello,
    I’m stuck with the following at the moment. I started smoking cannabis by the
    age of 15 and never had any problem with it. My grades did not decline and I
    smoked very responsible (only in weekends and vacation when there are no tests
    that I have to learn or make). But about 6 months ago I bought a bong and tried
    it out (of course), I took about 10-15 bong hits one after the other, and felt
    nothing. At that time I was sitting on a small hill smoking my bong and I
    decided, since it was not working, to return to my house. So I ran down the hill
    and BANG. Suddenly, totally unexpected it hit me. I was noting like I ever
    experienced with cannabis, I had strange thoughts about the world and myself and
    I could not control them at all, my heart was pounding very quick and very
    heavily. I thought I was going insane and felt like dying. Later that day these
    extreme feelings fainted, almost. In the past six months I experienced slight
    derealisation and depersonalisation and some anxiety, also I am much more
    sensitive to light then I was before. I feel a lot better now. I also went to a
    psychiatrist. But I did not got a satisfying answer from anyone, perhaps someone
    here knows. Some facts:
    – I did not have hallucinations and neither have them now
    – I am not paranoid
    – I have no family history of schizophrenia
    – I have been diagnosed with Asperger syndrome (no idea of that has to do
    anything with it)
    My question is: what exactly happened to me that day, am I more likely to be
    vulnerable for schizophrenia or other serious mental diseases; and is it a
    really bad idea for me to smoke cannabis again (did not do the pas six months to
    be sure)?
    I hope someone can clear some thins up for me.
    Thanks in advance,
    All love,

      1. Placed the comment wrong (see below). Should be here right? Also I have been thinking about your article and the following question came up: you say that while there has been an exponential increase of THC and cannabis usage in the past 50 years or so, the percentage of people with schizophrenia has not gone up.
        This is indeed a very important clue, but have you checked that the other factors remained constant? To illustrate what I mean lest look at the following example:
        In a population of 1000 people, 14 people developed schizophrenia at least once in their lifetime. In other word 1.4% of the population has or is going to have schizophrenia at least once. Also 300 of the 1000 people (30%) have smoked cannabis at least once, with an average THC percentage of 10. Also 600 of the 1000 people (60%) have tried crack cocaine at least once.
        Now 50 year later the numbers changed: 60% used at least once cannabis, with an average of 20% THC, 1.3% has or is going to have schizophrenia and 30% of the population tried crack cocaine at least once. Once might say that schizophrenia is not linked to cannabis usage, but there is actually no prove: because crack cocaine usage has been halved. Perhaps both substances play a role in the developing of schizophrenia. (the numbers here are totally made up and are just used to illustrate my question)
        Sorry, I’m not English, please correct me where I’m wrong (grammar, spelling).

    1. Eric, unless you are Bob Marley 10-15 bong hits, is a HUGE DOSE of THC. 1-2 bong hits would be good for most people. If it was a hard drugs like, coke, meth, heroin, or prescription painkillers you may have died.
      I wouldn`t presume to tell you what to do with your own body, but if you want to clean out start drinking water. It`s the same thing people do to pass a drug test. It might take awhile depending on your body makeup, more or less body fat. Also take Vitamin C, an all purpose detox substance.
      And if you do use it again BE CAREFUL!!!

      1. Thanks for your reply. Its 8 months since, and I feel better but still experiencing slight depersonalization. I can cope with it but it is still disturbing. Do you really think water can help, never read that? I could try it of course, do you have some references?
        All love,

  41. Thanks haha.
    Why not? You must have a valid reasoning if you do not agree with a theory. I do not think either that marijuana can cause schizophrenia, but you have to come with arguments, as it is not an absurd theory I think. Keeping other factors constant is a very important thing in science. Please consider my other question too (about using cannabis after a panic reaction, see the post of June 22, 2012 at 1:09 AM).
    I understand you have not much time, but I hope you will reply when you have the time for it.
    With all respect,

  42. Hello there MR.Lindsay A person that I know and have for a long time who is 14 has started smoking marijuana about once every 8-9 days to help deal with his OCD, worrying of the nails and cconstant stress caused for no apperent reason and it has helped him become a fun and happy person. He is worried that he may develope SF(Sorry can’t spell it) because thats what he does best. Worrie. So what would you reccomend my friend do? Stop taking Mary Jane and go back to being miserable or continue and risk the chance of SK. I will ask him if his family has a history of SK if so I will instruct him to stop based on factual non-anicdotal evidence and if his family does not have a history of SK then what should I tell him.

  43. I’m against the criminalization of MJ however I do think it can be addicting and eventually dangerous if used on a regular basis over years. It turns certain parts of your brain into mush and all the serious potheads I know are lazy.

    1. It certainly does not “turn parts of your brain into mush.” That’s not to say it has no effects on the brain. If you want to know my expertise for making such a statement, I know more about pot than anyone you will ever meet.

      1. “I know more about pot than anyone you will ever meet”. So how/where exactly did you obtain all this information besides searching the internet for scientific articles. Just curious… 🙂

        1. I was told something along those lines in the early 1990’s by the head of NORML at the time. He said that I knew more about pot than any nonspecialist he had ever met except for one guy in Alaska. This was before the Internet. That was mostly just due to research via books and journal articles in libraries at the time. I have continued researching after the Internet came on board, but to be honest, most of the best data came from libraries and not the Net. In addition, I have spoken with many of the top researchers themselves over the phone. I have been studying pot pretty intensively for over 30 years.

        2. Interesting! Do you have some references for me (books/Internet) so I can research further? That would be great. Also I was wondering if it is a bad idea to smoke marijuana after an drug induced anxiety disorder? I read a lot of material that says that marijuana can actually help improve anxiety, but does that also count for drug induced anxiety. Would really appreciate a reply!

        3. Eric, I am not sure. You already had a bad depersonalization episode due to marijuana. Now you want to smoke it again?! Well, you can, but be very careful. I am not too wild about underage kids smoking pot anyway. There seems to be good reasons to be against it.

        4. Thanks for your reply. Of course; if I feel any bad sensation again I will let it rest for some time and perhaps try it another time. I’m not in a hurry. I was just wondering if marijuana could also be beneficial for drug induced anxiety. Citing you article: “Anecdotally, many persons report relief from anxiety, depression, tenseness and anger from the use of marijuana.”. I’m under a lot of pressure sometimes and can’t find any method to relieve my stress. I thought I could give it a try, if it doesn’t work: no problem. It doesn’t have any long term side effects from just trying it a few times, doesn’t it?
          With all love, Eric.

        5. Well… I tried it now a couple of times and no negative effects. I just have to make sure that I’am feeling all right when I use it. Person, set, setting he? 🙂
          I will try a strain with more CBD, because as for now I don’t experience any benefits for my anxiety problem. I enjoy it, as a social event, but it would be better if it actually improves my condition. Do you have any suggestions for a cannabis strain or use pattern?

  44. I feel that being aware of your psychosis, or bring awareness into psychosis such as coping and affirmations. Everyone is so different that it’s hard to say what helps one may hurt another. One thing that is a major problem with schizophrenia, that isn’t discussed enough, is alcohol. Alcohol is actually way worse than marijuana for schizophrenia. I am now abstaining for any alcohol. I may have bipolar psychosis or something, but whatever it is alcohol makes me feel crappy even one or two beers. I am abstaining from drugs in general and alcohol. I am not pro drugs, I just think they shouldn’t become a fixation. the interesting thing is of all the people in my family who have mental illnesses, the ones who smoked pot never seemed to become unstable. Which may mean there are some healing benefits. I avoid it personally now as a moral choice.

  45. i can’t believe i read this entire article. it’s an interesting topic.
    my boyfriend has schizophrenia, as well as he smokes a lot of cannibis. Yet don’t think that it had anything to do with it since he told me he experienced symptoms when he was only 4 years old!
    i don’t think you have to worry while doing drugs unless you cause a lot of brain damage. the main causes of the disease are gentics and trama.
    i have experimented with cannibis and lsd. sometimes i have flashbacks of the lsd when i don’t sleep or get sick. but it will just be little things such as the celing moving. sometimes the flashbacks can be caused by cannibis, which is interesting to me.
    if cannibis can bring back the effects of lsd (which is similar to schizophrenia) what does that mean it could do to real mental disorders?

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