The medical consensus is that there is a real, if weak, connection between marijuana use and psychotic disorder. However, cannabis doesn’t cause the disorder, it only triggers it.
The oldest way of stigmatizing a drug is to link it to madness. This strategy goes at least as far back as the ancient Greeks. As far as cannabis goes, I assume many readers have watched Reefer Madness while high at least once.
The cackling, hollow-eyed, disheveled-haired dope fiend of the 1930s endured in the popular imagination into the 1970s. And there was plenty of anecdotal and even medical evidence to support this perception.
Indeed, a 2014 medical literature review from Yale University cites a source as early as 1845 that describes an episode of cannabis psychosis. On the strength of that example —plus hundreds of more case studies, surveys, and other medical reports — the researchers conclude that “cannabis may be a component cause in the emergence of psychosis, and this warrants serious consideration from the point of view of public health policy.”
But if you dig into this claim, you’ll see it’s a far cry from saying that a single puff will inevitably compel you to loosen your tie, maniacally seek out jazz music, and then jump out a window.
The medical consensus is that there is a real, if weak, connection between marijuana use and psychotic disorder. However, cannabis doesn’t cause the disorder, it only triggers it. In other words, you won’t get schizophrenia from smoking weed; but if you’re genetically or otherwise inclined to schizophrenia, heavy cannabis use can help the disease emerge. (Of course, there are caveats to and dissents from this consensus. This NPR report lays out these positions clearly and with absolutely no science-talk.)
Counterpoint: Cannabis Can Calm Your Inner Demons
That’s more or less the conclusion of a second literature review, this one from 2012 by researchers at the University of São Paulo and King’s College London.
One reason for such conflicting conclusions is the fact that marijuana not a simple drug. It contains some four hundred chemical components, about 60 of which are cannabinoids that have (poorly understood) biochemical effects on the human body.
The 2012 review examines, not the whole plant, but just two cannabinoids: THC and CBD. It’s the THC that gets us high and which, in high enough doses and with the right (or is it “the wrong”?) user, can cause “psychotomimetic symptoms”—that is to say “symptoms that mimic a psychotic break.”
On the other hand, CBD has no psychoactive effects. This is generally accepted. What the 2012 review contends, however, is that it actually works to mitigate the intoxicating effects of THC, just as the peaceable brown gargantua, Sanda, struggles to restrain the destructive rampages of Gaira, his green-haired brother. It therefore concludes that CBD might have a possible use as an antipsychotic medication.
Are You Going To Give Us A Straight Answer?
So, will smoking weed be the cause of your descent into madness, or will it be your deliverance? Perhaps, like SNL’s New Shimmer, it could be both.