Discusses the use of the dexamethasone suppression test in confirming a diagnosis of melancholia. The test is well tolerated by patients & no subjective, behavioral, or metabolic side-effects occur with single-dose administration. The DST is not suitable for screening unselected patients but should be uses when the clinician thinks it might help to answer a specific diagnostic question. Clinical applications are outlined & the need for further studies is outlined. 28 refs.