Auto accidents accelerate trauma disorder.

Crime, disaster and bereavement produce plenty of heartbreak, but a new study suggests that the single most significant trauma for city dwellers lurks on highways and streets. The culprit: automobile crashes.

Serious car accidents may yield roughly 28 severely distressed persons -- who meet criteria for post-traumatic stress disorder (PTSD) -- for every 1,000 adults in the United States, asserts psychologist Fran H. Norris of Georgia State University in Atlanta.

However, given the sparse data on people's reactions to car accidents, establishing cause and effect proves difficult, she notes. For example, key PTSD symptoms, such as sleep problems, lack of concentration and easily provoked startle responses, may contribute to, as well as result from, car crashes.

Norris directed a 1990 survey of 1,000 adults interviewed in four cities in North Carolina, South Carolina and Georgia. The project focused on participants' level of exposure and reactions to Hurricane Hugo, which devastated large areas of North and South Carolina in 1989. Interviwers also inquired about other traumatic events, including robbery; physical assault; sexual assault; death of a close friend or family member because of an accident, homicide or suicide; automobile crash serious enough to injure one or more people; military combat; and injury or property damage due to fire.

The sample was half black and half white, half female and half male, and evenly divided among younger, middle-aged and older adults. although the sample was not randomly chosen, the results provide a useful comparison of the frequency and severity of traumatic events across different social groups, Norris contends in the June JOURNAL OF CONSULTING AND CLINICAL PSYCHOLOGY.

Tragic deaths of loved ones occurred most often, striking 30 percent of the participants at some time in their lives and 5 percent in the year before the survey. Sexual assaults, cited by 4 percent of the sample, yielded the highest rate of current PTSD, nearly 14 percent. But serious car crashes presented the most adverse combination of frequency and emotional impact, Norris maintains. About 23 percent of the sample had survived such an incident, and nearly 3 percent cited an automobile accident in the past year. Norris found that 12 percent of all car-crash survivors suffered from PTSD at the time of the survey.

One in five people had experienced a violent event in the past year, in most cases unrelated to Hurricane Hugo, Norris says. Yound adults reported the greatest number of violent encounters. This finding coincides with evidence that 40 percent of young, urban adults encounter highly stressful events (SN: 3/30/91, p.198).

Whites reported more incidents of physical assault and tragic death than blacks, an unexpected findings that Norris cannot explain. However, blacks -- especially black men--reported the most stress in response to traumatic events.

The study also indicates that a person's risk of encountering traumatic events jumps dramatically over time, Norris says. For instance, within a year about 1 in 50 adults may experience a serious car crash, but 1 in 4 will experience this event at some time in their lives.