Psychiatric risk factors for motor vehicle fatalities in young men

Motor vehicle accident (MVA) fatalities are an important cause of death in young men. Psychiatric disorders have been shown to be risk factors for MVA, but only a few studies have investigated MVA fatalities.

A case-control study was carried out comparing 61 young male MVA fatalities in which the subject was the driver with an equal number of living male subjects matched for age (case by case with no more than 1 year's difference between case subjects and control subjects) with the accident group. We assessed both groups, using structured interviews and psychological autopsies.

Our results suggest that cluster B personality disorders (borderline and [or] antisocial) (OR 3.54; 95%CI, 1.38 to 16.01) and substance use disorders in the last 6 months (OR 4.33; 95%CI, 1.42 to 9.25) increased the risk of dying in MVAs. In addition, we observed an age effect, where differences in cluster B personality disorders and substance use disorders in the last 6 months were only significantly more prevalent in case subjects aged 26 years or over, compared with control subjects of the same age. Drivers under age 25 years appeared to be comparable with control subjects on all measures of psychopathology. Finally, this interaction between cluster B personality disorders and age over 26 years was the only significant predictor of car fatalities (adjusted OR 16.25; 95%CI, 1.67 to 158.10).

Borderline and antisocial personality disorders in which impulsive-aggressive behaviours play a central role and substance use disorders appear to be risk factors for young male deaths in MVAs. Interestingly, this effect seems to be specific to MVA case subjects aged 26 years or over.