In hand cigarette filled with cannabis (Getty Images/Anastassiya Bezhekeneva) A study this week reported an association between people’s medical records listing cannabis use disorder and both schizophrenia diagnoses and psychosis — but experts emphasized the data should not be used to draw causal conclusions about cannabis use and these risks.
In a study published in JAMA Network Open, the authors reported that the proportion of people with a new diagnosis of schizophrenia who had cannabis use disorder listed in their record increased after cannabis was legalized in Canada. The rates of nonspecified psychosis also increased during this time among people with this label in their record, said Dr. Daniel T. Myran, the lead author and a researcher at the Ottawa Hospital Research Institute.
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“Seven percent of people in Canada use cannabis nearly every day , and there’s now more people in the United States who use cannabis every day than drink alcohol every day ,” Myran told Salon in a phone interview. “I see this as a signal that this is something that could actually become a pretty important public health concern.”
Across the study period, the overall incidence of schizophrenia remained stable, and it has remained stable since the 1990s . The authors state that this “occurred because the incidence of schizophrenia increased among younger individuals while decreasing in older adults” during the study period.
Yet this is important to note considering cannabis use has significantly increased in the past decade .
“If cannabis use ‘causes’ schizophrenia, it is absolutely impossible that the rate of schizophrenia would not be going up with the rates of cannabis use increasing 1,000-fold,” said Dr. Peter Grinspoon, a cannabis specialist at Massachusetts General Hospital.
“If cannabis use ‘causes’ schizophrenia, it is absolutely impossible that the rate of schizophrenia would not be going up with the rates of cannabis use increasing 1,000-fold.”This isn’t the first time a link has been reported between cannabis and psychosis. The two have been tangled up together since the 1930s with the release of the anti-cannabis propaganda film, “ Reefer Madness ,” […]
New research continues to link marijuana with schizophrenia. Experts say it’s not so simple
