Smoking Cannabis Linked To Larger Brain Volume And Better Cognitive Function Later In Life

OG article by Benjamin Taub

February 12, 2026

A new study reveals that moderate lifetime cannabis use is associated with larger brain volumes in key regions and improved cognitive performance later in life. Analyzing data from over 25,000 adults aged 40–77, researchers found increased volumes in the hippocampus, amygdala, caudate, and putamen—areas critical for memory, learning, emotion, executive function, and motor control—among moderate users.

In a subset of 16,728 participants, these structural differences correlated with better results in cognitive tests for learning, processing speed, and short-term memory. Lead author Anika Guha noted surprise at the consistent positive associations, which contrast with acute negative cognitive effects from cannabis use. Benefits appeared strongest in moderate users and persisted even decades after cessation.

The findings suggest cannabinoids like THC may offer neuroprotective effects by modulating inflammation or neurodegeneration, potentially reducing age-related brain atrophy and dementia risk, especially in the hippocampus. However, adolescent use carries known psychiatric risks that do not seem to extend into later life.

Limitations include missing data on cannabis potency, strains, specific cannabinoids (THC, CBD, CBG), and gender differences, plus potential confounders. Published in the Journal of Studies on Alcohol and Drugs, the study indicates cannabis impacts brain health vary across lifespan stages, with possible protective benefits in adulthood.