Psychiatric Risk Factors for Motor Vehicle Fatalities in Young Men

Article excerpt

Background: 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.

Method: 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.

Results: 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).

Conclusion: 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.

(Can J Psychiatry 2005;50:838-844)

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Clinical Implications

* The presence of a cluster B personality disorder (borderline and [or] antisocial) may increase the risk of young men dying in an MVA.

* Having an alcohol or drug-related disorder may increase young men's risk of dying in an MVA.

* We observed an age effect, which could lead to more precise prevention programs targeting specific psychiatric problems in individuals aged over 25 years.

Limitations

* Sample size decreased statistical power owing to our stringent matching of cases and control subjects.

* This was a postmortem study.

* The generalization of findings may be limited.

Key Words: motor vehicle accident, borderline personality disorder, antisocial personality disorder, alcohol abuse and dependence, drug abuse and dependence, psychopathology

Abbreviations used in this article

CI confidence interval

ISC Interview Schedule for Children

K-SADS Schedule for Affective Disorders and Schizophrenia for School-Age Children

MVA motor vehicle accident

OR odds ratio

SCID-I Structured Clinical Interview for the DSM-IV

SD standard deviation

Motor vehicle accidents are the leading cause of death for individuals aged under 35 years and are a particularly important source of injury for young men (1). Accordingly, men have a threefold increased risk of being involved in a fatal crash, compared with women (1).

Several studies have been carried out to assess psychiatric risk factors in MVAs. These studies have shown that having an alcohol and (or) drug problem (2-5) and having a personality disorder increase the risk of road accidents (3,4,6). In addition, several pathological personality traits have been associated with MVAs. Among them, extreme social deviance or antisocial traits, low tension tolerance, impulsiveness, aggression or hostility, and emotional instability were shown to increase the risk of an MVA (3,4,7-10). However, because these studies have mostly been done on MVA survivors, the question still remains about the accuracy of generalizing these individuals' psychopathology to that of MVA driver fatalities. …