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New Study Suggests Schizophrenia Might Actually Lead to Cannabis Use

Not just the other way around.
Gavin Butler
Melbourne, AU

The notion that weed and schizophrenia are somehow related is by now a “water is wet” kind of non-statement. Scientists have been telling us for years that bongs aren’t good for the brain, and that heavy cannabis use—especially among adolescents—increases the risk of developing a psychotic disorder.

But new research indicates our understanding of the relationship might have been one-sided. Because schizophrenia, in fact, may be contributing to your desire to get high.


A study, published in Nature Neuroscience, states from the outset that “Cannabis use is a heritable trait that has been associated with adverse mental health outcomes.” The report then attempts to map the genetic coding that may lead someone to smoke weed. To do so, a team of scientists from the International Cannabis Consortium and a number of worldwide academic institutions—including the Queensland Institute of Medical Research and Radboud University, in the Netherlands—studied anonymous genetic data from more than 180,000 subjects. Many of those subjects had signed up for genetic testing site 23andMe, while others had participated in previous studies through the UK Biobank.

Overall, the scientists found 35 different genes associated with cannabis use. The strongest links were made to a gene known as CADM2, which in previous studies “has already been associated with risky behaviour, personality, and alcohol use”, said Jacqueline Vink, the study’s lead author.

Among their findings, researchers discovered a notable genetic overlap between those who typically used cannabis and those who used tobacco and alcohol. That’s not exactly splitting the atom: anyone who’s fraternised with stoners knows that many of them are also partial to a beer and a dart. But the study’s authors further noticed an overlap between those who typically used cannabis and those who were genetically predisposed to schizophrenia.

“Previous studies have often shown that cannabis use and schizophrenia are associated with each other,” Vink pointed out. “However, we also studied whether this association is causal.

“Our study showed that people with a vulnerability to develop schizophrenia are at increased risk of using cannabis.”

The scientists concluded that those who had the known genes for schizophrenia were directly predisposed to cannabis use—possibly, they suggest, as a form of self-medication. They also pointed out that this discovery does not disprove the scientific evidence for weed contributing towards schizophrenia.

Meaning it’s still probably a good idea to take it easy on the blunts.