Among 540 older adults across the dementia spectrum, those who used cannabis in the past six months performed just as well on cognitive tests as non-users—though problem cannabis use may be different.
Older adults who use cannabis and worry about cognitive effects, geriatricians, and neuropsychologists assessing cannabis-using patients.
What the researchers found
As cannabis use increases among older adults, a pressing question is whether it affects cognitive function in people already at risk for or experiencing cognitive decline. This study examined 540 older adults (age 65+) from a well-characterized observational cohort, spanning the full dementia continuum: cognitively intact, mild cognitive impairment (MCI), and dementia.
About 11% reported using cannabis in the prior six months, with the typical user consuming two to four times per month. When compared on a comprehensive neuropsychological battery covering five cognitive domains, cannabis users performed similarly to non-users across the board.
The researchers went beyond traditional statistical analysis, using propensity score matching—a technique that creates matched pairs of users and non-users who are otherwise similar—to strengthen the comparison. Even with this more rigorous approach, no cognitive differences emerged.
However, there was a signal in the subgroup analysis: among cannabis users, those with more severe cannabis-related problems (a risk factor for cannabis use disorder) may have performed differently on cognitive tests. This suggests a dose-response or problematic-use threshold that casual use doesn't cross.
The study can't rule out that cannabis users might have been higher-functioning to begin with (selection bias), or that the 11% who reported use might differ from non-users in unmeasured ways.
Why it matters
The 65+ population is the fastest-growing demographic of cannabis users, and many are using it while navigating age-related cognitive concerns. Knowing that moderate cannabis use doesn't appear to worsen cognitive test performance across the dementia spectrum is relevant for clinical counseling—though the caveat about problem use severity is equally important.
The numbers in context
N = 540, age 65+. ~11% reported past-6-month cannabis use. Median use: 2–4 times per month. No significant differences across 5 neuropsychological domains. Cannabis-related problem severity may be associated with cognitive outcomes among users.
How the study worked
Cross-sectional analysis of 540 older adults (65+) from a well-characterized observational cohort spanning cognitively intact, MCI, and dementia. Cannabis use assessed by standardized questionnaire (past 6 months). Comprehensive neuropsychological assessment across 5 domains. Analysis: multivariate and univariate traditional methods plus propensity score matching. Subgroup analysis of cannabis-related problem severity among users.
Who was studied
N=540 older adults aged 65 and over, mixed sex, observational cohort study
What this study cannot tell us
Cross-sectional design can't determine if cannabis use affects cognitive trajectories over time. Self-reported cannabis use (potential underreporting). The 11% use rate and moderate frequency mean heavy or daily users are underrepresented. Selection bias is possible—older adults who use cannabis may be healthier or more cognitively resilient to begin with. Neuropsychological tests may not capture subtle impairments in real-world functioning.
How to read the evidence
Well-characterized observational cohort with propensity score matching—stronger than simple cross-sectional analysis but still limited by potential selection bias.
When this study was published
Published in 2025 in JINS, reflecting increasing research attention to cannabis use in aging populations.
The bigger picture
This provides a reassuring counterpoint to concerns about cannabis and cognition in older adults. RTHC-00172 showed persistent brain network changes in chronic users even when sober, but this study suggests those neural changes don't necessarily translate to measurable cognitive deficits—at least at the moderate use levels typical of older adults. RTHC-00167 and RTHC-00178's cardiovascular findings remain relevant: even if cognition isn't affected, other health domains may be.
Replication
Not stated in abstract.
Funding
Not reported in abstract.
Conflicts of interest
Not reported in abstract.
Questions still open
- Would longitudinal follow-up reveal cognitive effects not visible cross-sectionally? Does cannabis use in older adults with MCI slow or accelerate progression to dementia? What level of cannabis-related problems begins to affect cognitive performance?
Read the original research
Cannabis use and cognition in older adults: Preliminary performance-based neuropsychological test results and directions for future research.
Journal of the International Neuropsychological Society : JINS, 31(7-8), 518-525
The Journal of the International Neuropsychological Society is a reputable journal focusing on the intersection of psychology and neuroscience.
Citation
Mulhauser, Kyler; Sullivan, Daniel; Bair, Jessica L; Correro, Anthony N; Pal, Subhamoy; Reader, Jonathan; Hampstead, Benjamin M; Giordani, Bruno. (2025). Cannabis use and cognition in older adults: Preliminary performance-based neuropsychological test results and directions for future research.. Journal of the International Neuropsychological Society : JINS, 31(7-8), 518-525. https://doi.org/10.1017/S1355617725101203
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