WHY IT MATTERS: Patients who use cannabis regularly and are concerned about long-term brain health now have large-scale data to discuss with their physician, though the findings underscore the importance of individualized conversations rather than blanket reassurance or alarm. CLINICAL OVERVIEW: Research drawing on large biobank datasets has examined whether cannabis use is associated with measurable changes in brain aging trajectories. The findings suggest a nuanced picture in which cannabis users may show some initial differences in brain age metrics, but the relationship between cannabis exposure and long-term neurological aging is not straightforwardly harmful or protective.