Marijuana use and subjective cognitive decline in middle-aged and older adults: Analysis of the behavioral risk factor surveillance system survey

Background: Marijuana impairs the brain development and function among adolescents, but little is known about whether marijuana use is associated with subjective cognitive decline (SCD) among adults. Objective: We investigated the cross-sectional association between marijuana use and past-year SCD in a representative sample of US adults aged 45 years and older. Methods: The study population included 100,685 participants from five cycles of the Behavioral Risk Factor Surveillance System (BRFSS). Participants self-reported their marijuana use in the past month and whether they experienced SCD or SCD-related functional limitations in the past year. Participants were categorized into past-month marijuana non-users and past-month marijuana users. Among users, they were further classified as occasional (<10 days) and frequent users (≥10 days). The weighted, multivariable logistic regression models were fitted to examine the association between marijuana use and past-year SCD, adjusting for age, sex, educational level, chronic disease status, and other potential confounders. Results: The sample included 94.2% (94,818/100,685) of past-month marijuana non-users and 5.83% (5867/100,685) of users. Among the users, 59.3% (3477/5867) were frequent users. Compared with past-month marijuana non-use, past-month marijuana use was significantly associated with higher odds of past-year SCD (OR = 1.70, 95% CI: 1.41, 2.05). The higher frequency was associated with higher odds of having past-year SCD in a dose-response manner (p Trend < 0.001). Similar associations remained for the SCD-related functional limitations. Conclusions: We found that past-month marijuana users reported higher rates of past-year SCD, a finding consistent with prior literature linking marijuana use with cognitive decline. Future prospective studies are warranted to confirm these findings.