The transition from cannabis induced psychosis to primary psychosis: factors that question the validity of the diagnosis “cannabis-induced psychosis”
European Psychiatry April 1, 2025 E. Rognli
A register-based study using Norwegian national patient data from 2010 to 2015 found that people initially diagnosed with substance-induced psychosis face a six-year cumulative risk of later developing schizophrenia of 27.6%. The risk was highest for those whose initial diagnosis was cannabis-induced psychosis, at 36%. These high transition rates raise questions about whether the initial diagnosis was correct or whether the psychosis was an early sign of a primary psychotic disorder masked by cannabis use. The authors argue that the diagnostic label 'cannabis-induced psychosis' overemphasizes substance use and overlooks other factors such as genetic vulnerability.