by Fernanda Pires,University of Michigan

Credit: Unsplash/CC0 Public Domain

Young adults who heavily use substances may report significantly poorer memory decades later, a new University of Michigan study suggests. Researchers tracked how frequently participants reported binge drinking and daily—or near-daily—use of alcohol, cannabis and cigarettes between the ages of 18 and 30. They then compared those patterns with self-reported poor memory at ages 50 to 65.

Thestudywas published in theJournal of Aging and Health.

"Substance use has both acute and long-term effects on health and well-being," said Megan Patrick, research professor at the Institute for Social Research and principal investigator of the Monitoring the Future Longitudinal Panel Study. "Poor memory is a common sign of early dementia. We examined whether young adult substance use was associated with poor memory decades later in midlife."

Identifying behaviors that shape brain health across the lifespan is critical. This is among the first longitudinal studies to link cumulative young adult substance use toself-rated cognitionin late midlife, Patrick said.

Young adulthood is a critical period for brain development. The study shows that substance use patterns established during this period may have lasting consequences on memory and cognitive health much later in life.

"Data like what we have from the MTF Longitudinal Panel study enable us to see these associations across multiple decades of development in the individuals who participate," Patrick said. "Identifying the risk factors that can lead to dementia is crucial for the prevention and treatment of cognitive decline."

Triple threat and addiction

The results suggest different substances may be associated with later memory through different routes—some through substance use disorder symptoms and others more directly.

For example,binge drinkingand frequent cannabis use in young adulthood were not directly linked with reporting poor memory in later life. Instead, they increased the risk of developing substance use disorders for people in their 30s, and those disorders were linked to poorer memory later in life. This suggests that treating substance use in midlife could help protect brain health.

Cigarette smoking showed a different pattern.Daily smokingin young adulthood predicted poorer memory in early midlife, regardless of smoking habits at age 35. These findings highlight the need to prevent smoking early in life, Patrick said.

"It's important for people to understand the long-term connections between their behaviors and later health and well-being," she said.

"Even if someone thinks their current substance use may not be problematic because they don't see it as affecting their health right now, there are still potential longer-term consequences to consider. In this case, we are finding some evidence of potential negative impacts of heavy young adult substance use on their cognitive functioning more than 20 years later."

Prevention and intervention efforts targeting young adults could significantly benefit long-term brain health, Patrick said.

"As we saw, this study demonstrates potential long-term detrimental impacts ofyoung adult heavy substance useon cognitive health later in life. It highlights the importance of early interventions," she said. "Understanding these risk factors and their trajectory across the lifespan will inform strategies to support cognitive health."

More information Megan E. Patrick et al, Young Adult Substance Use as a Predictor of Poor Self-Rated Memory Decades Later in Midlife, Journal of Aging and Health (2026). DOI: 10.1177/08982643261431007