The dexamethasone suppression test (DST) is being increasingly used in psychiatry, especially in the differential diagnosis of affective disorders. In light of this, the National Institute of Mental Health convened a workshop of clinical scientists drawn from neuroendocrinology, psychopathology, and general clinical psychiatry to review the evidence for the efficacy of the use of the DST in psychiatry. Specifically considered were DST's relevance to differential diagnosis, its use as a predictor of response to treatment, its relationship with other biologic variables, and technical issues. The panelists concluded that at this time there are no clear indications for routine use of the DST in diagnosis or clinical management of depression, although it is a useful research tool. Areas of potential utility include prediction of suicidal activity, prediction of relapse, and differential diagnosis.