Among children showing high levels of stress in reaction to exposure to community violence, researchers found stress hormone responses similar to children diagnosed with posttraumatic stress disorder.

Posttraumatic stress disorder (PTSD) symptoms include attention or sleep problems, intrusive thoughts, flashbacks, and other symptoms of psychological distress.

In previous research in children, Dr. Shakira Franco Suglia, at Harvard School of Public Health in Boston, identified a disruption of the stress hormone, cortisol, among those with PTSD. Suglia and colleagues have now found "similar effects among children living in urban communities who have not been diagnosed with PTSD," Suglia told Reuters Health.

The study involved 28 girls and 15 boys, 7 to 13 years old. Forty-six percent were Hispanic, 54 percent were white. Forty-two percent of the children had mothers with less than a high-school education, Suglia and colleagues report in the International Journal of Behavioral Medicine.

The researchers assessed mothers' reports of their children's exposures to hearing gunshots or witnessing other forms of community violence, and mother's and children's reports of symptoms typical of PTSD.

Suglia and colleagues found that children with higher stress scores had higher overall cortisol levels in saliva collected over a 3-day period — after the children awoke in the morning, after lunch, and dinner, and before bedtime.

Moreover, among children with higher stress scores, cortisol levels remained high in the late afternoon and evening — times when cortisol levels typically decline.

Cortisol is the primary stress hormone that can interfere with immune system responses and suppress the digestive system, the reproductive system and growth processes. This complex "natural alarm system" also communicates with regions of the brain that control mood, motivation and fear.

A growing body of evidence suggests "witnessing trauma may have far reaching health consequences for children," Suglia said.

Psychological distress in children may lead to behavioral and emotional problems and sustained high levels of the stress hormone, cortisol, may increase lifetime risk for cardiovascular and other health problems.

Besides the need for health care providers and parents to be aware of associations between childhood exposures to violence and stress, Suglia and colleagues call for continued investigations of associations between childhood stress and child health outcomes.