A recent study published in JAMA Psychiatry examines individuals impacted by substance abuse who visit an emergency department (ED) for treatment exhibit an 18.5 percent greater risk for developing schizophrenia within three years after their ED visit. This study was conducted by researchers at the Institute for Clinical Evaluative Services (ICES), Bruyère Research Institute, and The Ottawa Hospital, and holds the potential to help researchers and the public better understand the link between cannabis and mental health disorders.
For the study, the researchers conducted a cohort study involving ICES health records from 9,844,497 individuals between January 2008 and March 2022 and ages of 14 and 65 living in Ontario, Canada, with no prior history of schizophrenia or psychosis. A total of 407,737 individuals had a substance abuse-related ED visit, of which 13,784 of those individuals for substance-induced psychosis. In the end, the team discovered that 26 percent of individuals who used cannabis developed schizophrenia within three years after their ED visit compared to the general population.
“Our findings demonstrate an important increase in risk of being diagnosed with schizophrenia after an episode of substance-induced psychosis or substance use without psychosis – 163 times and 10 times higher than the background risk in the general population,” said Dr. Daniel Myran, who is affiliated with all three organizations and is lead author of the study.
In particular, the team discovered that cannabis users of younger ages and male sex (assigned at birth) exhibited a greater risk of developing schizophrenia, with more than 40 percent of those individuals between ages 14 and 24 being diagnosed with schizophrenia within three years of their corresponding ED visit, which was double the risk of females within the same age group.
“The high risk of cannabis use, particularly for young men, has important implications for public education and policies given global trends of increasing cannabis use and interest in the legalization of cannabis,” said Dr. Myran.
What new discoveries will researchers make about the link between cannabis and schizophrenia and other mental health disorders in the coming years and decades? Only time will tell, and this is why we science!
As always, keep doing science & keep looking up!