Study: Cannabis Use Associated with Better Cognitive Function in Adults Aged 40-77

New research from the University of Colorado Anschutz suggests that
cannabis consumption is associated with better cognitive function and
larger volumes in several brain regions in adults aged 40 to 77. Anika
Guha, PhD, a clinical psychologist and faculty research associate in the
Department of Psychiatry at CU Anschutz, noted that while bigger brain
volumes are not “always better,” researchers “often see smaller brain
volumes due to processes like atrophy and neurodegeneration,” which are
“often correlated with reduced cognitive function and increased dementia
risk.”

“In this study, we did see that most of the brain regions we looked at
demonstrated a positive relationship between brain volume and cognitive
performance. So in this sense, we could think of larger brain volumes in
the context of aging as possibly reflecting maintained brain volume and
preserved cognitive function, as opposed to say something like atrophy that
we expect to occur with age.” — Guha in an interview posted to the CU
Anschutz website

Guha noted that “for many” of the study’s outcome measures, cannabis
“moderation seemed to be best,” and that participants who consumed moderate
amounts of cannabis “generally had larger brain volumes and better
cognitive performance.”

“At the same time, there were a few measures, like volume of the right
amygdala and visual memory and learning, where the high use group had the
best outcomes,” Guha added, which she said “really suggests that there are
dose-dependent effects.”

Guha did note “as a caveat” that researchers “didn’t have access to
detailed information about the patterns of usage,” which she said “would be
helpful as additional contextual information.”

The study included information for the United Kingdom’s Biobank, which asks
participants to estimate how many times – from a set of ranges – they had
consumed cannabis over their lifetime. Researchers then grouped people
(26,362 in all) into no use, moderate use, and high use. Guhan called the
method “an imperfect way to group people,” but said it allowed researchers
“to approximate dose-dependent effects.”