Marijuana and mental illness
NIDA-funded research shows that when use starts during the teen years, marijuana is associated with impaired thinking, memory, and learning functions. It is also associated with a number of mental conditions, including psychosis (schizophrenia), depression, anxiety, substance use disorders, and suicidal thoughts or attempts. However, it is not yet clear if marijuana directly causes these issues or just makes them worse. Currently, there is strong evidence for the link between marijuana and psychosis in persons with a preexisting genetic or other vulnerability. Recent research also suggests that smoking high-potency marijuana every day could increase the chances of developing psychosis by nearly five times compared to people who have never used marijuana. Marijuana may contribute to the development or worsening of the mental illness, or it may reflect combinations of the above.