Study Finds Cannabis Usage in Middle Aged and Older Adults Associated With Larger Brain Volume, Better Cognitive FunctionOG

OG article by Matthew Hastings

February 4, 2026

CU Anschutz researchers analyzed UK Biobank data from 26,362 adults aged 40-77 (average 55) and found lifetime cannabis use associated with larger brain volumes in CB1 receptor-rich areas like the hippocampus, plus better cognitive performance in learning, memory, processing speed, attention, and executive function. Moderate use often showed the strongest positive links, though high use benefited some measures like visual memory and amygdala volume. One area, the posterior cingulate, showed lower volume with higher use. Sex differences appeared in several regions and cognitive outcomes, likely due to varying use patterns and endocannabinoid system variations. The study used self-reported lifetime use (none, moderate, high) but lacked details on cannabis type or potency. Lead researcher Anika Guha, PhD, called the consistent positive cognitive findings surprising given prior acute-use impairment data. She stressed nuanced effects and the need for balanced perspectives on cannabis in aging. Future studies may examine brain connectivity and related substances like psilocybin.