Stopping cannabis can help prevent schizophrenia in 25% young adults

Results

They examined 6 907 859 individuals with 45 327 cases of incident schizophrenia during follow-up across 129 521 260 person-years. The overall adjusted HR (aHR) for CUD on schizophrenia was slightly higher among males than females ; however, among 16–20-year-olds, the adjusted IRR (aIRR) for males was more than twice that for females

During 1972–2021, the annual average percentage change in PARFs for CUD in schizophrenia incidence was 4.8 among males and 3.2 among females. In 2021, among males, PARF was 15%; among females, it was around 4%.

Young males might be particularly susceptible to the effects of cannabis on schizophrenia. At a population level, assuming causality, one-fifth of cases of schizophrenia among young males might be prevented by averting CUD. Results highlight the importance of early detection and treatment of CUD and policy decisions regarding cannabis use and access, particularly for 16–25-year-olds.

Reference:

Hjorthøj, C., Compton, W., Starzer, M., Nordholm, D., Einstein, E., Erlangsen, A., . . . Han, B. (2023). Association between cannabis use disorder and schizophrenia stronger in young males than in females. Psychological Medicine, 1-7. doi:10.1017/S0033291723000880