According to the results of a recently published study by researchers from the University of Michigan, substance use between the ages of 18 and 30 years is linked to poorer memory in midlife, with different substances affecting cognitive health through different mechanisms. The study was funded by the National Institute on Drug Abuse (NIDA) and published in the Journal of Aging and Health, and the data was obtained from the Monitoring the Future Longitudinal Panel Study.

As part of the study, the researchers assessed substance use patterns between the ages 18 and 30 years and examined their association with self-reported memory outcomes in midlife, in the age range between 50 and 65 years. The study evaluated three key substance use patterns in young adulthood: binge drinking, near-daily cannabis use, and daily cigarette smoking, as well as their long-term impact on cognitive health.

It was found that daily smoking was directly associated with poorer memory in midlife, regardless of whether individuals had quit, suggesting a lasting effect on the developing brain. In addition, alcohol and cannabis use were linked to memory impairment indirectly, by increasing the risk of substance use disorders in early adulthood, which contributed to poorer cognitive outcomes later in life. As self-reported memory decline is an early indicator of cognitive impairment and dementia, these findings also highlight the importance of targeting substance use in young adulthood for prevention.

“As we saw, this study demonstrates potential long-term detrimental impacts of young adult heavy substance use on cognitive health later in life. It highlights the importance of early interventions,” said Megan Patrick, research professor at the Institute for Social Research at the University of Michigan and the study’s principal author, in a press release. “Understanding these risk factors and their trajectory across the lifespan will inform strategies to support cognitive health.”