Major Depressive Disorder and Driving Behavior Among Older Adults.

Importance: Depression and antidepressant use are independently associated with crash risk among older drivers. However, it is unclear what factors impact daily driving that increase safety risk for drivers with depression.

Objective: To examine differences in naturalistic driving behavior and safety between older adults with and without major depressive disorder (MDD).

Design, Setting, And Participants: A prospective longitudinal cohort study was conducted among older adults (≥65 years) from the Driving Real-World In-Vehicle Evaluation System Project collected from July 1, 2021, to December 30, 2023. The sample included 85 participants with MDD and 310 participants without. Neurological, clinical, mood, and neuropsychological tests were collected annually. Daily driving behavior was recorded using a commercial data logger. Statistical analysis was performed from January 31 to June 24, 2024.

Exposure: MDD and antidepressant usage.

Main Outcomes And Measures: Linear mixed models with propensity score weighting compared slopes of driving behaviors over time (trips taken at night, speeding, hard braking, entropy, and radius of gyration) between groups.

Results: In a sample of 395 participants, 85 were classified as individuals with MDD (mean [SD] age, 69.6 [6.1] years; 60 [70.6%] female; 8 [9.4%] non-Hispanic Black and 77 [90.6%] non-Hispanic White) and 310 as individuals in the control group without depression (mean [SD] age, 70.1 [5.1] years; 153 [49.4%] female; 40 [12.9%] non-Hispanic Black and 270 [87.1%] non-Hispanic White). Adults with MDD had greater depressive symptoms (mean [SD], 8.35 [5.35] vs 2.33 [2.72]; difference, 6.02; 95% CI for difference, 5.17 to 6.85; P < .001), comorbidities (mean [SD], 4.08 [2.07] vs 2.79 [1.67]; difference, 1.29; 95% CI for difference, 0.87 to 1.70; P < .001), used more antidepressants (mean [SD], 0.94 [0.81] vs 0.27 [0.54]; χ21 = 65.8; P < .001), and had a higher number of medications (mean [SD], 3.80 [3.27] vs 1.98 [2.21]; χ21 = 21.0; P < .001) compared with controls at baseline. Longitudinal analysis demonstrated an association between adults with MDD and hard braking (mean [SE], 3.17 × 10-4 [7.30 × 10-5] vs 6.70 × 10-5 [4.00 × 10-5]; difference, 2.50 × 10-4; 95% CI for difference, 1.74 × 10-4 to 4.61 × 10-4; P < .001) and hard cornering events per trip (mean [SE], 0.80 [0.64] vs 0.57 [0.25]; difference, 0.23; 95% CI for difference, 0.08 to 1.06; P = .04), greater distances driven from home (mean [SE], 31.19 [7.35] vs 7.76 [3.80] km; difference, 23.43; 95% CI for difference, 0.28 to 15.2; P < .001), more unique destinations visited (mean [SE], 0.34 [0.10] vs -0.27 [0.03]; difference, 0.61; 95% CI for difference, 0.14 to 0.54; P < .001), and higher random entropy (mean [SE], 0.01 [0.01] vs -0.02 [0.00]; difference, 0.03; 95% CI for difference, -0.03 to -0.01; P < .001) over time.

Conclusions And Relevance: In this longitudinal cohort study of older drivers, adults with MDD demonstrated distinct and riskier driving behaviors than those in the control group without depression, with higher rates of hard braking, cornering, and unpredictability in driving patterns over time. Routine depression screening and tailored interventions are essential for enhancing driving safety and maintaining independence among older adults with MDD. Comprehensive care approaches addressing both mental and physical health are crucial for this vulnerable population.