Cannabis, psychosis, and violence: case reports and comprehensive evidence review
Frontiers in Psychiatry July 21, 2026 Kenneth P. Finn, Robin M. Murray, Elizabeth Stuyt et al.
Cannabis use, especially high-potency products with THC concentrations above 10%, has been linked to rising psychosis cases from 1995 to 2010. Psychosis has multiple causes including genetics, childhood adversity, and drug use. This perspective argues that cannabis-associated violence deserves more attention, presenting high-profile media cases where THC was the only substance involved or cannabis use preceded psychosis and violence. Toxicology often fails to test for THC. The evolving evidence on cannabis, psychosis, and violence should inform medical screening, law enforcement, and policy.