Older adults with major depressive disorder (MDD) exhibit riskier driving behaviors than their nondepressed peers, including hard braking, cornering, and unpredictable driving patterns, new research showed.
Data for the study came from commercial vehicle data trackers installed in participants’ vehicles. After about a year of follow-up, investigators found that MDD was associated with an increase in the amount and severity of risking driving, even after controlling for antidepressant use.
Late-life depression often goes undiagnosed, and the new findings highlight the importance of routine depression screening and targeted interventions to ensure driving safety among older adults, the study team said.
“By using longitudinal, real-world driving data rather than controlled settings or self-reports, the study provides robust evidence of how MDD influences driving behaviors in day-to-day contexts,” first author Ganesh M. Babulal, PhD, OTD, with the Department of Neurology, Washington University School of Medicine in St Louis, told Medscape Medical News.
“By analyzing the influence of antidepressant use and overall medication load, the study disentangles the effects of MDD from those of driver-impairing medications, further clarifying the unique contributions of depression to driving behaviors,” Babulal noted.
The study was published online on December 30 in JAMA Network Open.
Road Risks
As the number of older adults grows, safe driving practices in this age group become increasingly crucial. By 2050, one quarter of drivers in the United States will be older than 65 years. MDD affects about 8% of US adults and is linked to cognitive impairments that may compromise driving safety.
Prior studies revealed a link between depression and increased car crash risk, regardless of age. And earlier research by Babulal and colleagues showed that older adults with depression were three times more likely to receive a marginal or failing score on a standardized road test.
To further study the issue, Babulal and colleagues examined the impact of MDD on naturalistic driving behaviors among older adults using longitudinal data.
Participants were recruited from the Driving Real-World In-Vehicle Evaluation System Project, where their daily driving behaviors were recorded using commercial vehicle data loggers installed in their personal vehicles.
The cohort included 85 adults with MDD (mean age, 69 years; 71% women) and 310 adults without MDD (mean age, 70 years; 49% women). The majority of participants in both groups were non-Hispanic White individuals.
Based on intercepts, adults with MDD had a propensity toward riskier driving habits with a higher frequency of speeding events and spending more time on the road than those without MDD, they found.
Additionally, during a mean of 1.1 years of follow-up, compared with older adults without MDD, those with MDD exhibited significantly more hard braking (P < .001) and hard cornering events per trip (P = .04) over time. They also traveled farther from home and visited more unique destinations (P < .001 for both).
Over time, older adults also displayed increased entropy in driving patterns (P < .001), indicated less predictable driving routes.
“Driving unpredictability, as evidenced by increased random entropy, highlights the unique challenges posed by MDD in maintaining safe driving practices,” the researchers wrote.
Adjusting for antidepressant use, which could impair driving, or total medication burden did not change the findings, suggesting MDD independently affects driving.
“Most importantly, our findings demonstrate that MDD — a common and treatable illness in older adults — was associated with an increase in both the amount and magnitude of risky driving behaviors over time,” the researchers wrote.
The researchers noted that the study did not account for changes in depression severity over time and other psychiatric conditions co-occurring with MDD were not adjusted for. Also, situational factors like weather or traffic conditions were not assessed.
Clear Clinical Implications
There is a “pressing need” for targeted interventions to manage and mitigate the driving risks associated with late-life depression, the researchers wrote.
“The study emphasizes the need for interventions tailored to the mental health and driving behaviors of older adults. These could include cognitive retraining, driver rehabilitation programs, and routine depression screening to enhance road safety and preserve independence,” Babulal told Medscape Medical News.
“Encouraging older adults with MDD to self-regulate their driving habits (e.g., avoiding night driving or high-traffic situations) and educating them about potential driving challenges related to their condition can enhance safety,” he added.
Commenting on this study for Medscape Medical News, Ipsit Vahia, MD, McLean Hospital, Belmont, Massachusetts, and Harvard Medical School, Boston, said it “adds nuance to our understanding of how depression can impact driving among older adults.”
“While the connection between depression and a higher incident of crashes is known, this study demonstrates an association with riskier driving behaviors such as speeding,” Vahia said. “It highlights the importance of clinicians proactively initiating discussion of driving and safety when working with older adults with depressive symptoms.”
This work was funded by grants from the National Institutes of Health and National Institute on Aging. Babulal had no relevant disclosures. Vahia had served as a consultant for Otsuka.
Johnathon Center
Read More