Increase Seen in Cases of Schizophrenia Linked to Cannabis Use Disorder
By Elana Gotkine HealthDay Reporter
FRIDAY, Feb. 7, 2025 -- The proportion of incident cases of schizophrenia associated with cannabis use disorder (CUD) almost tripled from the prelegalization to legalization of nonmedical cannabis periods, according to a study published online Feb. 4 in JAMA Network Open.
Daniel T. Myran, M.D., M.P.H., from the Ottawa Hospital Research Institute in Ontario, Canada, and colleagues conducted a population-based cohort study among 13,588,681 people aged 14 to 65 years without a history of schizophrenia to examine changes in the population-attributable risk fraction (PARF) for CUD associated with schizophrenia after liberalization of medical cannabis and legalization of nonmedical cannabis in Canada.
Of the participants, 0.9 percent had CUD. The researchers found that 0.7 percent of individuals in the cohort developed schizophrenia (0.6 percent in the general population and 8.9 percent of those with CUD). From the prelegalization to legalization periods, there was an almost threefold increase in the PARF for CUD associated with schizophrenia from 3.7 to 10.3 percent. The PARF in the postlegalization period varied from 18.9 to 1.8 percent among men aged 19 to 24 years and women aged 45 to 65 years, respectively. Over time, the annual incidence of schizophrenia was stable, while the incidence of psychosis not otherwise specified (NOS) increased from 30.0 to 55.1 per 100,000 individuals in the postlegalization versus the prelegalization periods. During the study, there was a steady increase in the PARF for CUD associated with schizophrenia, with no accelerations observed after cannabis policy changes. After medical cannabis liberalization, increases in the PARF for CUD-associated psychosis NOS accelerated.
"Ongoing research is needed on long-term trends in the incidence of psychotic disorders associated with changes in cannabis policy," the authors write.
One author disclosed ties to the pharmaceutical industry.
Disclaimer: Statistical data in medical articles provide general trends and do not pertain to individuals. Individual factors can vary greatly. Always seek personalized medical advice for individual healthcare decisions.
© 2025 HealthDay. All rights reserved.
Posted February 2025
Read this next
Mental Health, Neurodevelopmental Diagnoses in Publicly Insured Children on the Rise
WEDNESDAY, April 30, 2025 -- The percentage of publicly insured children receiving any mental health or neurodevelopmental disorder diagnosis significantly increased between 2010...
Risky Health Behaviors Tied to Poorer Mental Well-Being, General Health in Midlife
MONDAY, April 28, 2025 -- Risky health behaviors, both current and cumulatively over time, are associated with poorer mental well-being and self-reported health, according to a...
Burnout Still High for Veterans Health Administration Health Care Workers
MONDAY, April 28, 2025 -- Burnout remains above prepandemic levels for health care workers at the U.S. Veterans Health Administration (VHA), according to a study published online...
More news resources
- FDA Medwatch Drug Alerts
- Daily MedNews
- News for Health Professionals
- New Drug Approvals
- New Drug Applications
- Drug Shortages
- Clinical Trial Results
- Generic Drug Approvals
Subscribe to our newsletter
Whatever your topic of interest, subscribe to our newsletters to get the best of Drugs.com in your inbox.