Insurance companies take note: Mental stress and life changes may play a bigger role in determining who will have an automobile accident than demographic factors such as age and sex.
That finding is one of several linking mental illness and personality traits to accidents, and further research could help prevent them, Dr. Ming T. Tsuang of the Brockton-West Roxbury VA Medical Center in Massachusetts writes in the current American Journal of Psychiatry.
Among the findings of several studies summarized by Tsuang and his colleagues:
* People with personality disorders, such as paranoia or depression, are 144 percent more likely than the general population to be in an accident. But the accident rate for schizophrenics is almost identical to that of the general population.
* One in five drivers who had fatal accidents had had "accutely disturbing experiences" -- usually quarrels -- within six hours before the accident.
* People who used "minor tranquilizers" such as Valium were almost five times as likely as others to be involved in serious accidents.
* The personality traits most associated with accidents were inability to control anger and hostility, immaturity, difficulty with authority figures, belligerence and a tendency toward risk-taking.
If future studies show that people with certain psychiatric diagnoses are prone to accidents, Tsuang writes, then "some type of remedy or intervention could . . . [improve] the driving habits of these people."