A new study published in the journal JAMA Network Open has found that cannabis legalization in Canada is associated with a significant increase in new cases of schizophrenia linked to cannabis use disorder (CUD). The study, which analyzed data from over 13.5 million Ontario residents, revealed that the proportion of new schizophrenia cases tied to CUD rose from 4% before legalization to 10% after.
The research used healthcare visits data to track changes in how medical cannabis liberalization and non-medical cannabis legalization affected CUDs linked to new schizophrenia diagnoses. Researchers found a notable increase in emergency department visits and hospitalizations for CUD, with the number of individuals requiring care rising by 270%.
Conversely, the percentage of new schizophrenia cases tied to CUD before diagnosis increased from 7% to 16%. The study’s authors estimate that up to 10% of new schizophrenia cases could have been prevented if those seeking emergency care for a CUD had stopped using cannabis.
Dr. Daniel Myran, lead researcher and Canada Research Chair in Social Accountability at the University of Ottawa, emphasized the urgent need for targeted prevention strategies, particularly for younger populations who appear at greatest risk from heavy cannabis use.
Source: https://www.news-medical.net/news/20250205/Rising-cannabis-use-disorder-cases-contribute-to-growing-schizophrenia-diagnoses.aspx