Young Adult Substance Use as a Predictor of Poor Self-Rated Memory Decades Later in Midlife.

ObjectivesWe examined longitudinal associations between young adult heavy substance use and late midlife poor self-rated memory and whether problematic substance use in early midlife mediated the associations.MethodsData were from the Monitoring the Future Longitudinal Panel Study. Analyses included individuals ages 50-65 in 2018-2023 who provided longitudinal data starting at age 18 in 1976-1991.ResultsYoung adult heavy use of all substances was directly associated with higher odds of late midlife poor self-rated memory. These associations were fully mediated by early midlife substance-use disorder symptoms for binge drinking and cannabis use, but not mediated for pack+/day cigarette smoking.DiscussionSustained heavy substance use in young adulthood appears to represent a cumulative risk factor for cognitive decline in late midlife. Examining risk factors, including substance use, across the life course may be crucial for earlier identification of risk for cognitive decline.