The clinical use of the dexamethasone suppression test in DSM-III affective disorders: correlation with the severe depressive subtypes of melancholia and psychosis.

The utility of the dexamethasone suppression test (DST) as an adjunct in the diagnosis of major depression remains controversial. While the research utility of the DST has been confirmed, the clinical utility has been questioned. We studied 166 consecutive admissions to a general, non-research unit who either met DSM-III criteria for major depression of had depressive symptoms associated with other DSM-III diagnoses. Using a 5 micrograms/dl criterion, non-suppression of serum cortisol after dexamethasone was observed in 63% of patients with DSM-III major depression. Patients with the most severe subtypes of major depression (melancholia and psychosis) showed both the highest rate of serum cortisol non-suppression and the highest post-DST serum cortisol concentrations. These findings from the clinical setting where the test, if found useful, will be used ultimately suggest that the DST is both sensitive and specific for the diagnosis of major depression. Future research will determine the potential role of the DST as an adjunct to the clinical assessment and management of patients with major affective disorder.