Distinct neuroanatomical correlates of DBQ-derived illegal, irritable, and aggressive driving tendencies in healthy adults: an exploratory structural MRI study.

Background: Hazardous driving encompasses multiple forms of aberrant behavior that have been associated with increased crash involvement and unsafe driving outcomes. Although, structural MRI studies have linked regional brain morphology to driving performance and driving-related errors, evidence regarding the neuroanatomical correlates of distinct Driving Behavior Questionnaire (DBQ)-derived hazardous driving tendencies remains limited in large community-based samples of healthy adults. Methods: We analyzed data from 1,070 individuals undergoing routine brain health checkups who completed the DBQ and structural MRI. Three theoretically derived hazardous driving domains were examined: illegal, irritable, and aggressive driving. Participants were classified into higher-tendency and reference groups using predefined domain-specific thresholds. Multivariable logistic regression models were constructed using age, sex, driving frequency, and z-transformed regional brain volumes as explanatory variables. Stepwise variable selection based on the Akaike Information Criterion (AIC) was applied. Leave-one-out cross-validation (LOOCV) was used to evaluate model robustness and the stability of selected neuroanatomical correlates. Results: Male sex was consistently associated with all three hazardous driving domains, whereas younger age was specifically associated with aggressive driving. The multivariable models demonstrated moderate discriminative performance, with mean AUCs under LOOCV of 0.735 for illegal driving, 0.757 for irritable driving, and 0.796 for aggressive driving. Illegal driving was primarily associated with insular and sensorimotor regions, including the precentral and postcentral gyri. Irritable driving was associated with a broader network involving thalamic, striatal, temporolimbic, and posterior cortical regions. Aggressive driving showed a more focused pattern centered on the caudate, putamen, and right lingual gyrus. Notably, the right caudate and right lingual gyrus were common to both irritable and aggressive driving models. The direction of these associations remained stable across LOOCV iterations. Conclusions: Distinct DBQ-derived hazardous driving tendencies were associated with partially divergent yet overlapping regional brain volumetric patterns. These findings suggest that illegal, irritable, and aggressive driving may reflect partially distinct neurobehavioral processes related to risk regulation, emotional reactivity, and habitual aggressive responding. Although independent replication is required, these hypothesis-generating findings provide an initial neuroanatomical framework linking brain structure to distinct hazardous driving tendencies in neurologically healthy adults.