WHY IT MATTERS: If you are a parent, caregiver, or young adult considering cannabis, this research underscores why medical guidance, age-appropriate restrictions, and honest conversations about brain development should be part of any decision about use. CLINICAL OVERVIEW: Large-scale longitudinal research continues to reinforce what clinicians in cannabis medicine have long recognized: the adolescent brain is uniquely vulnerable to cannabinoid exposure, and early use is associated with elevated risk of psychotic disorders in adulthood. This does not mean cannabis inevitably causes psychosis, but it does mean that age of onset, frequency of use, and genetic predisposition are critical variables that deserve serious clinical attention.