A preliminary study to be presented at the American Stroke Association's International Stroke Conference 2026 suggests that subtle changes in older adults' driving habits may provide early warning signs of cognitive decline or dementia. The research, part of the Driving Real-World In-Vehicle Evaluation System (DRIVES) project at Washington University in St. Louis, followed 220 adults aged 65 and older for over five years. Participants were free of dementia at the start, but 17% developed cognitive impairment during follow-up, most later diagnosed with Alzheimer's disease.
The study used car sensors to track driving behavior, including speeding, hard braking, and collisions, and brain MRI scans to measure white matter hyperintensities—areas of damage caused by reduced blood flow. Researchers found that participants with greater white matter damage drove less, took fewer trips, followed more repetitive routes, and made more driving errors. Notably, damage in the back of the brain, which processes visual and movement coordination, was most strongly linked to unsafe driving and crashes.
"Driving habits in older adults can reveal early changes in brain health," said study author Chia-Ling Phuah, M.D., M.M.Sc., associate professor at Barrow Neurological Institute. "Even small shifts in daily driving patterns can offer important clues about brain changes—sometimes before traditional memory and thinking symptoms are noticeable."
An intriguing finding was that participants taking blood pressure medications, especially ACE inhibitors, were less likely to exhibit risky driving behaviors, even when brain damage was present. This effect was independent of blood pressure control. "One especially promising finding was that people taking blood pressure medications, particularly ACE inhibitors, tended to maintain safer driving habits even when their brain scans revealed more damage," Phuah said. "This suggests that these medications may help support brain health as we age."
Nada El Husseini, M.D., M.H.Sc., FAHA, chair of the American Heart Association's 2023 scientific statement on cognitive impairment after stroke, commented: "What's surprising is that people taking ACE inhibitors were less likely to have impairment in their driving despite the extent of white matter disease. The impact of ACE inhibitors on cognitive function and driving safety requires further investigation."
According to the American Heart Association 2026 Heart and Stroke Statistics, about 6.9 million adults 65 or older in the U.S. were living with Alzheimer's disease in 2024. The study's findings suggest that monitoring driving behavior with in-vehicle data loggers could help identify older adults at higher risk for unsafe driving and cognitive problems. However, the study had limitations, including a small, mostly white and college-educated sample, and self-reported medication use.
"These findings suggest that cognitive screening and brain imaging might be considered for people with driving difficulties," El Husseini added. The researchers call for larger, more diverse studies to confirm the results. For more on brain health, see the American Heart Association's Stroke Hub.
