Salivary cortisol responses to dexamethasone in adolescents with posttraumatic stress disorder

Objective: Previous studies of adults with posttraumatic stress disorder (PTSD) have found various abnormalities in the regulation of the hypothalamic-pituitary-adrenal axis, including enhanced suppression of cortisol following low-dose dexamethasone. The purpose of the present study was to investigate salivary cortisol responses to low-dose dexamethasone in adolescents with PTSD. Method: Forty-eight adolescents (20 with current PTSD, 9 trauma controls without PTSD, and 19 healthy nontraumatized controls) were enrolled in the study. On day 1, baseline saliva samples were obtained at 8 A.M. and 0.5 mg of dexamethasone was administered at 11 P.M. Cortisol and dexamethasone levels were assessed at 8 A.M. the following day. Results: Adolescents with current PTSD showed no difference in the suppression of salivary cortisol in response to low-dose (0.5 mg) dexamethasone compared to trauma controls without PTSD and nontraumatized controls. More severely affected PTSD subjects with co-occurring major depression showed higher pre- and post-dexamethasone salivary cortisol levels compared to controls. Conclusions: The present study did not find evidence for enhanced suppression of salivary cortisol at 8 A.M. following low-dose dexamethasone in multiply traumatized adolescents with PTSD. This result differs from findings in adults with PTSD. Further investigations of hypothalamic-pituitary-adrenal axis abnormalities in traumatized children and adolescents are needed.