J Stud Alcohol Drugs

Cannabis use tied to larger brain, better cognition in older adults

February 6, 2026

In a UK Biobank analysis of more than 500,000 adults aged 40 to 70 years, lifetime cannabis use was associated with larger volumes in CB1 receptor–rich regions (including the hippocampus, amygdala, caudate, and putamen) and with better performance in learning, processing speed, and short-term memory. Even individuals reporting cannabis use limited to adolescence showed more favorable brain and cognitive measures than non-users. Associations varied by sex, underscoring biological heterogeneity.

Clinical takeaway: While causality cannot be inferred, results suggest cannabis may affect brain health differently across the lifespan.

Source:

Guha A, et al. (2025, December 11). J Stud Alcohol Drugs. Lifetime Cannabis Use Is Associated with Brain Volume and Cognitive Function in Middle-Aged and Older Adults. https://pubmed.ncbi.nlm.nih.gov/41379083/