Subtle alterations in everyday driving behaviour among older adults may provide crucial early warning signs of brain changes and increased dementia risk, according to groundbreaking new research. A comprehensive study has revealed that shifts in how frequently people drive, the routes they take, and their safety behind the wheel could signal underlying damage to the brain's white matter, which is closely linked to cognitive decline.
Monitoring Driving Patterns for Brain Health Clues
The American research team followed 220 motorists with an average age of 73 for five years, all living in St. Louis, Missouri, who did not have dementia when they enrolled in the study. Data collection spanned an impressive nine-year period from 2016 to 2024, with participants undergoing continuous monitoring of their in-vehicle driving metrics.
Researchers tracked multiple aspects of driving behaviour including:
- Trip frequency and distance travelled
- Destination patterns and route variation
- Safety events such as time spent speeding
- Collision incidents and near-misses
- Hard braking and aggressive cornering patterns
All participants underwent MRI brain scans at the study's outset, with just under half receiving a second scan at least twelve months later. Annual clinical and cognitive assessments complemented the driving data, creating a comprehensive picture of brain health and driving behaviour.
White Matter Damage and Driving Changes
The study found that greater white matter damage in the brain was consistently linked to specific driving pattern changes. Older adults with more extensive white matter hyperintensities tended to drive less frequently, take fewer trips, stick to familiar routes, and make more motoring errors. These patterns were particularly pronounced among the 17% of participants who went on to develop cognitive impairment during the study period.
Professor Chia-Ling Phuah of the Barrow Neurological Institute in Phoenix, the study's lead author, explained: "How often people drive, where they go, and how much they vary their routes may signal underlying damage to the brain's white matter. These findings suggest that even small shifts in daily driving patterns can offer important clues about brain changes - sometimes before traditional memory and thinking symptoms are noticeable."
Blood Pressure Medication's Protective Effect
One of the study's most surprising findings concerned participants taking blood pressure medications. Adults aged 65 and older who were taking these medications, particularly ACE inhibitors, were significantly less likely to exhibit risky driving habits, even when brain scans revealed substantial white matter damage.
Professor Phuah noted: "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. This effect was observed regardless of whether their blood pressure levels were at target levels, suggesting these medications may help support brain health as we age."
Real-World Implications for Older Drivers
The research has significant implications for how we monitor cognitive health in older adults. Professor Phuah suggests that monitoring driving behaviour using commercial in-vehicle data loggers could help identify older motorists at higher risk for unsafe driving, loss of independence, and subtle cognitive problems before traditional symptoms emerge.
Among participants who developed cognitive impairment, higher white matter hyperintensity burden was linked to a greater likelihood of unsafe driving practices and more crashes. Particularly concerning was the finding that participants with white matter changes in the back of the brain - responsible for processing visual information and movement - were at even higher risk of accidents than those with changes in other brain areas.
Personal Stories Highlight the Challenge
The study's findings resonate with real-world experiences of families dealing with cognitive decline. Larry Duncan, a retired business owner from Pinehurst, North Carolina, experienced subtle driving changes before his Alzheimer's diagnosis in 2023. His wife Pam recalled: "Larry was fine driving in familiar areas. But in new places where he had to make quick decisions, he became anxious."
As his cognitive challenges progressed, Duncan's doctor advised him to stop driving - a decision his wife describes as heart-breaking but necessary. Pam, who now volunteers for the American Stroke Association, emphasised: "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."
Expert Response and Future Directions
Duke University Neurology Professor Nada El Husseini, who was not involved in the study, welcomed the findings while calling for further investigation. She commented: "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. The impact of ACE inhibitors on cognitive function and driving safety requires further investigation."
Professor El Husseini also suggested that "these results suggest cognitive screening and brain imaging might be considered for people with driving difficulties," highlighting the potential clinical applications of the research.
The study findings are scheduled for presentation at the American Stroke Association's International Stroke Conference in New Orleans, marking an important step in understanding how everyday activities like driving can serve as windows into brain health and cognitive function in older adults.
