Background: Knowledge of pathogenic mechanisms and predictors of relapse in major depressive disorder is still limited. Hypothalamic-pituitary-adrenocortical (HPA) axis dysregulation is thought to be related to the development and course of depression.
Methods: We investigated whether dexamethasone/corticotropin-releasing hormone (DEX/CRH) test parameters were related to the occurrence of relapse in 45 outpatients with clinically remitted major depression. The DEX/CRH test was administered before and after 8 weeks of antidepressant treatment.
Results: Posttreatment maximal adrenocorticotropic hormone (ACTH) and maximal cortisol levels, as well as delta ACTH and delta cortisol levels, were significantly higher (all p < .05) among patients who relapsed (n = 22) compared with patients in whom no relapse occurred (n = 23). Higher posttreatment maximal cortisol response on the DEX/CRH test was associated with shorter "relapse-free survival" (p = .05).
Conclusions: In outpatients with clinically remitted major depression, higher posttreatment maximal cortisol levels on the DEX/CRH test were associated with relapse of major depression.