WHY IT MATTERS: If you are a parent, caregiver, or young adult considering cannabis, this study reinforces that adolescent brain development is a critical window where unsupervised use may carry serious long-term psychiatric risks that do not necessarily apply to adult medical patients under clinical guidance. CLINICAL OVERVIEW: A new longitudinal study links adolescent cannabis use to increased risk of later bipolar and psychotic disorder diagnoses, adding to a growing body of evidence that the developing brain is uniquely vulnerable to cannabinoid exposure. While this research does not apply directly to adult medical cannabis patients, it reinforces what clinicians in cannabis medicine have long emphasized: age of onset matters enormously, and adolescent use carries a fundamentally different risk profile than supervised adult medical use.
Adolescent Cannabis Use Linked to Doubling Risk of Psychotic and Bipolar Disorders
Nearly half a million teens were tracked in this study, and the data shows cannabis use during adolescence meaningfully increases the chance of serious psychiatric diagnoses in early adulthood. A large longitudinal cohort study published in JAMA Health Forum tracked 463,396 adolescents and found that cannabis use between ages 13 and 17 was associated with approximately double the risk of psychotic and bipolar disorders by age 26. Elevated risks for depression and anxiety were also observed.