NEW YORK (Reuters Health - August 14, 2000) - Why do some children develop post-traumatic stress disorder (PTSD) in response to extremely stressful experiences while others do not? According to a recent report in the American Journal of Psychiatry, characteristics of the children themselves and of their family situations make some kids more likely to suffer this debilitating condition. "It appears that the child at greatest risk for developing PTSD is the vulnerable anxious child who is exposed to violence, especially violence in the family," report Dr. Raul R. Silva and colleagues from New York University/Bellevue Hospital Center in New York.

PTSD is characterized by intrusive thoughts, avoidant behavior, and feelings of fear and anxiety after a traumatic event. The investigators looked at 59 children aged 3 to 18 referred to an inner-city psychiatric center following trauma. Among these children, some of whom reported more than one event, 24% were physically abused, 22% were sexually abused, 39% witnessed serious domestic violence, and 54% had experienced other kinds of trauma, such as being robbed, mugged, or seriously wounded, surviving a fire, or witnessing others suffer violent incidents.

"This inner-city population experienced a distressingly high rate of trauma," Silva and colleagues note. "However, less than a quarter of subjects who had experienced trauma, despite exposure to a serious stressor, met full criteria for PTSD."

Of the 59 children, 46% had no symptoms of PTSD, 32% had some symptoms, and 22% met the diagnosis for PTSD. The authors point out that there were no differences in age, gender, or ethnic background among the three groups, nor did the kind of traumatic event suffered appear to make much difference.

Silva and colleagues also looked for relationships between PTSD and other psychiatric disorders in the children. They report that those with pre-existing anxiety disorders were more likely to develop PTSD, which is an anxiety disorder itself.

The investigators found that conduct disorder and oppositional defiant disorder--both conditions in which children's behavior tends to be hostile, aggressive and uncontrolled--were much less common among children who developed PTSD. Forty percent of the children with no symptoms and 58% of those with some symptoms had one of these disorders, compared with only 15% of those who met the diagnosis of PTSD.

The researchers report other important differences between the children who were diagnosed with PTSD and those who had some symptoms but did not meet the diagnosis. Although both groups reported intrusive thoughts about the original event, those with PTSD suffered much more from these, and were many times more likely to report avoidant behavior and feelings of fear and anxiety--the other two hallmarks of the condition.

"Trauma that threatens family integrity appears to make a strong contribution to the development of PTSD," Silva and colleagues write. "Identification of a child at risk in a provocative home situation would seem an important target for preventive intervention."

And which children are at most risk? The researchers suggest that "pre-existing clinical conditions and individual constitutional factors" help determine which children will develop PTSD. They emphasize, however, that even faced with one or more traumatic experiences, most children in this study did not develop PTSD or even some of its symptoms.

Silva and colleagues conclude that "there is a reassuring resiliency in children, even in the harshest environment."

SOURCE: American Journal of Psychiatry 2000;157:1229-1235.