Older adults' driving habits may provide early warning signs of cognitive decline and dementia, according to preliminary research to be presented at the American Stroke Association's International Stroke Conference 2026. The study of 220 adults aged 65 and older found that white matter damage in the brain was linked to decreased driving, fewer trips, repetitive routes, and more driving errors, particularly among those who later developed dementia.
Researchers tracked participants' driving behavior for over five years using car sensors that monitored speeding, collisions, hard braking, and hard cornering. Brain imaging studies conducted within the first year measured white matter hyperintensities—areas of damage caused by reduced blood flow to brain tissue. The analysis revealed that participants with more white matter damage tended to drive less and showed sharper declines in their ability to change driving routes and habits.
During the follow-up period, 17% of participants developed cognitive impairment, with most later diagnosed with Alzheimer's disease. Among this group, higher white matter hyperintensity burden was linked to greater likelihood of unsafe driving practices and more crashes. White matter damage located in the back of the brain—responsible for processing visual information and coordinating movement—was particularly associated with higher crash risk.
"Participants with white matter hyperintensities located in the back of the brain were at even higher risk of crashes than those with changes in other brain areas, making them more likely to experience unsafe driving episodes and car accidents over time," explained study author Chia-Ling Phuah, M.D., M.M.Sc., an associate professor at Barrow Neurological Institute in Phoenix.
A significant finding emerged regarding blood pressure medications. Participants taking medications to manage high blood pressure, especially angiotensin-converting enzyme (ACE) inhibitors, were less likely to exhibit risky driving behaviors compared to those not taking blood pressure medication. This protective effect was observed even when brain scans revealed significant white matter damage, suggesting these medications may help support brain health 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 noted. "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 strokes, commented on the implications. "What's surprising about these findings is that people taking ACE inhibitors were less likely to have impairment in their driving despite the extent of white matter disease. These results suggest cognitive screening and brain imaging might be considered for people with driving difficulties."
The study's findings align with established medical guidelines regarding blood pressure management and brain health. According to the 2025 American Heart Association High Blood Pressure Guideline, early treatment is recommended for people diagnosed with high blood pressure to maintain brain health and cognition, as research confirms blood pressure affects cognitive function and dementia risk.
Researchers suggest that monitoring driving behavior with commercial in-vehicle data loggers could help identify older adults at higher risk for unsafe driving, loss of independence, and subtle cognitive problems. This approach might detect changes before traditional memory and thinking symptoms become apparent, potentially allowing for earlier intervention.
The study has several limitations, including a small sample size and lack of diversity among participants—most were white, college-educated adults. Medication use was self-reported, which could introduce errors. The research team plans larger studies with more diverse participants to confirm and extend these findings.
For caregivers and family members, the research highlights the importance of paying attention to subtle changes in driving patterns. Pam Duncan, whose husband Larry was diagnosed with Alzheimer's disease in 2023, shared her perspective as a caregiver. "In early-stage cognitive impairment, symptoms can be subtle, and driving is one of them. Don't ignore these changes. As caregivers, our role is to support independence while having the courage to make tough decisions."
The study was conducted as part of the Driving Real-World In-Vehicle Evaluation System (DRIVES) project based at Washington University in St. Louis. Data was collected over a nine-year period from 2016 to 2024, with participants undergoing annual clinical and cognitive assessments alongside their driving monitoring.
