Teenage Cannabis Use Linked to 52% Higher Schizophrenia Risk

A large study of nearly 700,000 people found that teenagers with cannabis use disorder have a significantly higher risk—about 52% greater—of developing schizophrenia and other psychiatric conditions compared to peers using other substances.

The risk appears age-dependent, with adolescents showing increased vulnerability while adults with cannabis use disorder showed lower relative risk, possibly because cannabis may trigger earlier onset in those already predisposed.

Overall, the findings suggest that heavy cannabis use during brain development may contribute to or accelerate serious mental illness, though causation is still being studied.