title: Enhanced suppression of cortisol following dexamethasone administration in posttraumatic stress disorder.
abstract: OBJECTIVE
  The authors investigated the possibility of enhanced negative feedback sensitivity of the hypothalamic-pituitary-adrenal (HPA) axis in posttraumatic stress disorder (PTSD) by using a low dose of dexamethasone.
  
  
  METHODS
  Baseline blood samples were obtained at 8:00 a.m., and 0.5 mg of dexamethasone was administered to 21 male patients with PTSD and 12 normal age-comparable men at 11:00 p.m. Cortisol and dexamethasone levels were measured 9 and 17 hours after dexamethasone administration.
  
  
  RESULTS
  After correction for differences in dexamethasone levels, the PTSD patients showed greater suppression of cortisol in response to dexamethasone than did the normal subjects. This was true even in patients meeting concurrent diagnostic criteria for major depression.
  
  
  CONCLUSIONS
  The data support earlier studies showing that HPA abnormalities in PTSD are different from those seen in depression and suggest that the low-dose dexamethasone suppression test may be a potentially useful tool for differentiating the two syndromes and further exploring differences in their pathophysiology.
authors.affiliation: Department of Psychiatry, Yale University School of Medicine, New Haven, Conn.
authors.forename: R
authors.initials: R
authors.lastname: Yehuda
authors.forename: S M
authors.initials: SM
authors.lastname: Southwick
authors.forename: J H
authors.initials: JH
authors.lastname: Krystal
authors.forename: D
authors.initials: D
authors.lastname: Bremner
authors.forename: D S
authors.initials: DS
authors.lastname: Charney
authors.forename: J W
authors.initials: JW
authors.lastname: Mason
mesh_terms: D000328:Adult; D003866:Depressive Disorder / Q000097:blood / Q000175:diagnosis / Q000503:physiopathology; D003907:Dexamethasone; D003937:Diagnosis, Differential; D006801:Humans; D006854:Hydrocortisone / Q000097:blood*; D007030:Hypothalamo-Hypophyseal System / Q000503:physiopathology; D008297:Male; D010913:Pituitary-Adrenal System / Q000503:physiopathology; D013313:Stress Disorders, Post-Traumatic / Q000097:blood / Q000175:diagnosis* / Q000503:physiopathology
chemical_list: D003907:Dexamethasone; D006854:Hydrocortisone