Lifetime Cannabis Use, Brain Volume, and Cognitive Function in Middle-Aged and Older Adults
March 26, 2026
At the March CMCR Investigators’ Meeting, Anika Guha, Ph.D., of the Rocky Mountain Cannabis Research Center at the University of Colorado Anschutz Medical Campus, presented research on lifetime cannabis use and its associations with brain volume and cognitive functioning in middle-aged and older adults. Her talk examined whether cannabis may have different effects on the aging brain than those typically reported in younger populations.
Dr. Guha began by noting that cannabis use is increasing among older adults, many of whom report using it to address pain, sleep problems, and anxiety. At the same time, relatively little is known about the long-term effects of cannabis on brain health in aging populations. She emphasized that much of the existing literature has focused on adolescents and young adults, often highlighting adverse effects during periods of active brain development.
She then reviewed prior work from her group suggesting that age may moderate cannabis-related effects. In smaller studies of older adults, cannabis use was associated with differences in endocannabinoid responsivity, acute cognitive effects, and regional brain morphology. These findings helped motivate a larger analysis using UK Biobank data.
Using self-reported lifetime cannabis exposure in a large cohort of middle-aged and older adults, Dr. Guha and colleagues found that cannabis use was associated with larger volumes in several subcortical and limbic regions, including the putamen, hippocampus, amygdala, and caudate. Cognitive analyses also showed better performance among cannabis users than non-users across several domains, particularly among moderate users. Similar patterns were observed in a subgroup whose cannabis use reportedly occurred only before age 25.
In closing, Dr. Guha emphasized that these findings do not establish that cannabis is beneficial, but they do challenge overly broad assumptions about uniformly negative effects on the aging brain. They highlighted the need for future studies with better measures of dose, product type, biomarkers, longitudinal change, and dementia-related outcomes.
Anika Guha, PhD
Faculty Research Associate
University of Colorado Anschutz Medical Campus
Dr. Guha’s research examines the effects of cannabinoids and psychedelics on neurocognition and mental health across the lifespan, with a particular focus on adolescence and older adulthood. She previously worked with Dr. Beau Ances at Washington University in St. Louis, received her Ph.D. in Clinical Psychology from UCLA, and completed postdoctoral training at the University of Colorado Anschutz Medical Campus, where she focused on translational neuroimaging research. Dr. Guha currently works in the Cannabis, Health, and Addiction Over the Lifespan (CHAOS) Lab directed by Dr. Kent Hutchison.