Increased adrenocorticotropin suppression following dexamethasone administration in sexually abused adolescents with posttraumatic stress disorder.

Evidence suggests that individuals with posttraumatic stress disorder (PTSD) have an enhanced sensitization of the hypothalamic--pituitary--adrenocortical (HPA) axis. However, few studies in adolescents have been performed. Fourteen sexually abused adolescent inpatients with DSM-IV PTSD (12 female, two male; mean +/- SD age, 16.2 +/- 1.9 years) were compared with 14 adolescent hospitalized controls (11 female, three male; mean age, 15.7 +/- 2.0 years). All subjects underwent a standard dexamethasone suppression test (DST, 1 mg given orally at 2300 h) five days after admission. Baseline blood samples were obtained at 0800 h, and the following day, adrenocorticotropin (ACTH) and cortisol levels were measured at 0800, 1600, and 2300 h. Clinical assessment included the Impact of Event Scale, Stanford Acute Stress Reaction Questionnaire, Beck Depression Inventory, and Coping Inventory for Stressful Situations. Post-DST ACTH levels were significantly lower in PTSD than in control adolescents (at 0800 h: P < 0.005; at 1600 h: P < 0.001; at 2300 h: P < 0.05). In patients, post-DST cortisol levels were reduced but not significantly. No correlations were found between ACTH and cortisol levels and time elapsed since trauma. These results demonstrate that sexually abused adolescents with PTSD show ACTH hypersuppression to DST suggesting enhanced glucocorticoid receptor sensitivity in the pituitary.