Relationship Between Cannabis Use and Immediate, Delayed, and Working Memory Performance Among Older Adults

Cannabis is increasingly accessible and use is increasing rapidly among older adults as laws change and cannabis becomes more frequently prescribed in healthcare settings. Past research identified cognitive effects of cannabis use among adolescents and young adults that can persist for several weeks after intoxication, though little is known about how these effects generalize to older adults. Participants (N = 1348) were drawn from the Health and Retirement Study (HRS) and were categorized as current occasional users (up to once/week in the past year, n = 36), current frequent users (once per week or more in the past year, n = 92), past users (n = 334), and non-users (n = 886). Participant ages ranged from 50 to 98 (M = 67.25, SD = 10.68). Uncontrolled, one-way ANOVAs and controlled ANCOVAs were used to examine between-group differences on immediate and delayed wordlist memory and working memory (serial sevens). When controlling for age, gender, education, and minority status, current frequent users demonstrated significantly worse immediate memory performance compared to past and non-users. However, this difference could have been the result of acute, residual effects of past-month cannabis use among current users. In controlled analyses, there were no differences between groups on delayed or working memory. Findings indicate that greater than weekly cannabis use may result in attentional and short-term memory deficits. Further, these effects may be mitigated by sustained abstinence. Limitations including sample size and measures of cannabis use warrant future studies to replicate and build upon these findings.