Biological correlates of direct exposure to terrorism several years postdisaster.

BACKGROUND

It is important to understand long-term biological and psychiatric correlates of intense exposure to terrorism.

METHODS

We assessed psychiatric diagnoses and biological stress measures in 50 healthy, highly exposed Oklahoma City bombing survivors recruited from a bombing registry 6 1/2 to 7 years postdisaster, comparing them with demographically matched, nonexposed community members. The Diagnostic Interview Schedule (DIS) determined Axis I psychiatric diagnoses. Participants' salivary cortisol levels were obtained at 8 am, and physiologic assessment measured participants' heart rate and blood pressure responses to a bombing-related interview.

RESULTS

Eleven survivors with posttraumatic stress disorder (PTSD) had significantly higher cortisol levels than did both non-PTSD survivors and controls. Survivors with and without PTSD did not differ in any autonomic reactivity measure, whereas the total survivor group had significantly higher reactivity than controls in all measures. Positive correlations occurred between several autonomic reactivity measures, but none between cortisol and autonomic measures.

CONCLUSIONS

Results differentiate the autonomic and cortisol systems relative to terrorism exposure. Findings support research associating PTSD with hypothalamic-pituitary-adrenal (HPA) axis changes, whereas autonomic reactivity appeared to be a more generalized trauma response. Correlation statistics substantiated a lack of connection between the 2 biological systems. Follow-up could elucidate the long-term course of these stress systems and eventual health status in survivors, in view of the medical morbidity noted in PTSD studies.