Research published in the JAMA Health Forum has found that teenagers who use marijuana face significantly increased risks of psychiatric disorders. Young people who used cannabis showed higher chances of being diagnosed with psychotic disorders, anxiety, and depression over time, according to findings reported by NPR.
The cohort study, which tracked health data from 460,000 teenagers in Northern California through age 25, excluded youth with prior symptoms of mental illness. Those who used marijuana doubled their risk of developing bipolar disorder and psychotic disorders including schizophrenia. Columbia University psychiatrist Dr. Ryan Sultan described the findings as “very, very, very worrying.”
The study’s authors noted that “adolescent cannabis use was associated with increased risk of incident psychiatric disorders, particularly psychotic and bipolar disorders,” and suggested the results “could inform the development of clinical and educational interventions for parents, adolescents, and clinicians, as well as protective policies to prevent or delay adolescent cannabis use in the context of expanding cannabis legalization.”
Among the 460,000 teenagers studied, nearly 4,000 were diagnosed with either bipolar or psychotic disorders. Both conditions rank among the most serious and disabling mental illnesses, with schizophrenia alone carrying substantial societal costs—the disorder’s societal cost has been calculated at $350 billion a year, according to NPR.
Growing Potency Compounds Concerns
Scientists are particularly concerned about the potency of modern cannabis products. Today’s cannabis contains two to three times more THC—the ingredient responsible for the high—than products in the past. Cannabis use during adolescence poses particular risk since the brain is still developing critical neural connections during those years, and previous studies show such use may have lasting effects on cognitive functions important to academic performance.
Additional research has found that in 2025, more Americans were addicted to marijuana but fewer were seeking help for the problem, according to the Associated Press.
This article is an AI-assisted summary. All facts and figures are drawn from the original report: https://www.breitbart.com/health/2026/02/22/study-very-worrying-marijuana-use-among-teens-brings-higher-risk-of-psychotic-disorders/