Repost from the old site.
The original post in its native form was far too long, so I have decided to break it up into seven different posts, in addition to this post. The separate sections are listed below.
The original post, what is left of it, is here.
For an examination of the evidence of whether or not cannabis causes actual structural damage to brain cells, axons or dendrites, see here.
For an analysis of neuropsychological batteries of cannabis users to determine whether or not they suffer brain damage, see here.
For an analysis of EEG testing of cannabis users to discover evidence of brain damage, see here.
For an analysis of studies looking at cerebral blood flow in cannabis users, see here.
For a summary comparing the effects of cannabis on the brain compared to other drugs, see here.
For a summary of the findings of cannabis and brain damage, see here.
A common accusation of those who oppose the use of cannabis is that it causes schizophrenia. We deal with that notion in this post. Along the same lines, cannabis is said to cause schizotypal symptoms in users. Schizotypal symptoms are best seen as a subset of schizophrenic symptoms, or like subsyndromal schizophrenia.
I would argue against this notion just on impressionistic grounds: I have known hundreds or thousands of cannabis users over the years, and only a few of them were schizotypal in any way. Of the cannabis users I know now, none of them seem to be schizotypal in any way. I had a former girlfriend who I was convinced was schizotypal.
Other than that, I’m not sure if I’ve met any. But anyway, enough of my impressionistic stuff, on to the studies.
Cannabis users have shown elevated scores on schizotypy scales in six different studies. These scales have some serious problems, in my opinion (here is an example of one). Also, after people stop using cannabis, schizotypy scales revert to normal, so there are no permanent effects.
I am not sure what all of this adds up to.
Most cannabis users that I know and have known, over a period of 35 years, even very heavy users, are not strange, odd, weird, or schizotypal-type persons, and they do not become more this way with increased years of use. Most people I knew like that either didn’t use cannabis, or they were already pretty strange before they started using it. In many cases, they were less strange after using cannabis than before.
Heavy cannabis users sometimes seem to me to have to slow speech, to be mentally slow, dulled, forgetful (I know one pothead who asks me the same question multiple times after I have answered it), lazy, unmotivated and apathetic, but I haven’t noticed any tendency for them to be schizotypal.
I have known a few people who acted pretty weird when they smoked pot (one was a 15-yr-old boy). In general, most people like that just quit using cannabis.
Along these same lines, studies continue with rats. Giving rats cannabis in utero, in adolescence and in early adulthood led to long-lasting memory problems, increased social anxiety and steady-state anxiety and decreased social interaction. Once again, this is interesting, but over a lifetime, I have not noticed a tendency for regular cannabis users to become increasingly socially avoidant or nervous.
It is a common sequence that after years of good effects, people start reporting that pot makes them anxious. They usually phrase this as, “It makes me paranoid.” In general, these people tend to stop using the drug.
Repost from the old site.