title: The influence of psychiatric comorbidity on the dexamethasone/CRH test in major depression.
abstract: BACKGROUND
  The outcome of the dexamethasone/corticotropin-releasing-hormone (DEX/CRH) test in depressed patients is heterogeneous. The present study investigated whether comorbidity of anxiety or somatoform disorders might be an explaining factor for this finding.
  
  
  METHODS
  The DEX/CRH test was administered in 36 pure major depressive outpatients, 18 major depressive outpatients with a comorbid anxiety and/or somatoform disorder, and 43 healthy controls. Patients were free of psychotropic medication. Group differences in responsivity to the DEX/CRH test were analysed.
  
  
  RESULTS
  Depressive patients with comorbidity showed a significant lower cortisol response compared to pure depressive patients (p = 0.04) and controls (p = 0.003). Group differences between MDD patients with and without comorbidity in cortisol responses disappeared after adjustment for post-DEX cortisol concentrations (p = 0.34).
  
  
  CONCLUSIONS
  An enhanced suppression of cortisol to 1.5 mg DEX is present in a subgroup of depressed patients with psychiatric comorbidity. Distinct hypothalamic-pituitary-adrenal (HPA) axis dysfunctions are revealed when comorbidity is taken into account.
authors.affiliation: Department of Psychiatry, Leiden University Medical Center, PO Box 9600, 2300 RC Leiden, The Netherlands. G.Veen@lumc.nl
authors.forename: Gerthe
authors.initials: G
authors.lastname: Veen
authors.forename: Roel H
authors.initials: RH
authors.lastname: Derijk
authors.forename: Erik J
authors.initials: EJ
authors.lastname: Giltay
authors.forename: Irene M
authors.initials: IM
authors.lastname: van Vliet
authors.forename: Johannes
authors.initials: J
authors.lastname: van Pelt
authors.forename: Frans G
authors.initials: FG
authors.lastname: Zitman