WHY IT MATTERS: If you are a parent, caregiver, or young adult considering cannabis use, this research reinforces that delaying use until the brain is more fully developed, generally past age 25, is one of the most important harm reduction strategies available. CLINICAL OVERVIEW: Large-scale longitudinal research continues to reinforce the clinical concern that adolescent cannabis exposure is associated with elevated risk of psychotic disorders and other serious mental health conditions in adulthood. From a neurobiological standpoint, the adolescent brain is undergoing critical endocannabinoid system maturation, and exogenous cannabinoid exposure during this window may disrupt neurodevelopmental trajectories in ways that increase vulnerability to psychosis, particularly in genetically predisposed individuals.