A major study of more than 463,000 adolescents has found that teens who use cannabis face roughly double the risk of later developing psychotic disorders and bipolar disorder. The research, published in JAMA Health Forum, tracked participants from ages 13 to 17 through age 26.
Researchers analyzed electronic health records from routine pediatric visits between 2016 and 2023. Adolescents who reported cannabis use in the previous year showed significantly higher rates of psychotic disorders, bipolar disorder, depression, and anxiety. On average, cannabis use preceded diagnosis by 1.7 to 2.3 years.
"Adolescent cannabis use is associated with double the risk of incident psychotic and bipolar disorders," said Lynn Silver, a study co-author and program director at the Public Health Institute. The study accounted for prior mental health conditions and other substance use.
Lead author Kelly Young-Wolff noted that cannabis remains common among teens, with over 10 percent of those aged 12 to 17 reporting past-year use. Average THC levels in some products now exceed 20 percent, raising further concerns about long-term effects on developing brains.
