WHY IT MATTERS: Teenagers and parents should know that cannabis use during adolescence is not simply a lifestyle choice but a neurological exposure that may meaningfully increase the risk of serious, lifelong psychiatric conditions. CLINICAL OVERVIEW: Adolescent cannabis use carries meaningful psychiatric risk, particularly for conditions like psychosis and bipolar disorder, during a developmental window when the brain is especially vulnerable to THC’s effects on dopaminergic and endocannabinoid signaling. The association between early cannabis exposure and a doubling of risk for these disorders reflects both biological susceptibility and the potency of today’s high-THC products compared to earlier decades.