Substance Abuse and Mental Illness: Effects of Marijuana and Other Drugs on Developing Psychosis

• Rates of cannabis use are approximately 2 times greater in persons with psychosis
• Cannabis has negative effects on cognition that are qualitatively similar in the general population, in people with psychotic disorders and in people at risk for psychotic disorders
• Adolescence is an important but vulnerable period of development for both the general population and especially for individuals at high risk for psychotic disorders