Schizophrenic about Marijuana

Canada went Reefer Madness this past week:

A pair of articles in the Canadian Journal of Psychiatry has resurrected the “reefer madness” argument about marijuana and its links to mental illness.

Cannabis use can trigger schizophrenia in people already vulnerable to the mental illness — and this fact should shape marijuana policy, argue two psychiatric epidemiologists in this month’s journal.

The British press has been agog with this issue for some time now, blathering on about the mental health dangers of pot.

Of course, you can’t expect the press to be responsible with this kind of stuff. They don’t, for the most part, know a thing about the issue they’re reporting nor do they consider that worth their bother. The press will breathlessly report “New study shows eating wheat causes instant death to humans!” while blithely munching on a sandwich, blissfully oblivious to the obvious question of why they don’t know anyone who died from eating wheat.

Surprisingly, there has been very little hype about this here in the states so far. But I wouldn’t be surprised if we were subjected to this hysteria soon.

The problem is that I know very little about schizophrenia. Of course, I’m not alone in this ignorance. Certainly the majority of our public policy leaders know less than I do, and even to psychiatric researchers it’s still a bit of a mystery. The following is necessarily unscientific and meant to give a simple layman’s overview (those with more knowledge please correct me if I’m wildly off).

1. People tend to be pre-disposed to developing schizophrenia, based on genetic factors. This doesn’t mean that full blown schizophrenia will develop if you’re pre-disposed, but it means that it’s very unlikely to develop if you’re not.
2. There may be a long period in youth when a person is developing or has developed schizophrenia but does not yet have overt exterior symptoms.
3. The population of people pre-disposed to schizophrenia is extremely small.
4. Scientists learned that, of the even smaller group who develop schizophrenia, a seemingly high percentage smoked marijuana.
5. After some study, they found a link between smoking marijuana and schizophrenia. That, of course meant nothing in terms of causality. As many people properly pointed out, that could as easily be explained as being self-medication (marijuana eased the symptoms of schizophrenia, so those with the condition sought it out).
6. After further study, scientists learned that people who were pre-disposed to schizophrenia and smoked pot when they were young, were more likely to develop full-blown schizophrenia than those who were pre-disposed to schizophrenia and didn’t smoke pot when they were young. This appeared, in the minds of a few researchers, to nail shut the case that marijuana was a factor in inducing schizophrenia (or at least in worsening the condition or speeding up the onset). Keep in mind that the conclusion comes only from their interpretation of the correlation.
7. Another interpretation of the correlation that makes as much or more sense from the data (but is not reported) is that the pre-conditions of schizophrenia cause people to seek out marijuana.

This last point is discussed in a post by writch over at Stop The Drug War Speakeasy.

…we know that the bodies of schizophrenics are trying to make lots of natural endocannabinoids. Why the body does this is still a mystery, but it makes clear why they would want to smoke pot compulsively.

It also makes pretty clear that compulsive pot smoking is a symptom, not a cause, of schizophrenia.

Unfortunately, the disease is one in which, throughout youth, the afflicted appear ‘normal’. The full force of the disease doesn’t normally appear until after adolescence is complete. This allows for the improper assignment of a ’cause’ to what seems obviously a biological issue to me, and many reputable scientists.

He goes on to note that the results of this study, rather than being a call for restrictions on the use of marijuana in the general population (most of whom are not pre-disposed to the problem), might have a more useful result — understanding that compulsive marijuana use by teens may be a symptom of schizophrenia, and using that as a diagnosis tool.

I’d be very curious to hear more about this particular interpretation.