This study considered dexamethasone suppression test (DST) results, Winokur 's familial subtyping, and the presence or absence of melancholia according to DSM-III criteria as potential predictors of response to ECT. Familial subtype and DST results independently predicted outcome after ECT, but melancholia did not. Relationships between outcome and several other traditional items tested for comparison generally agreed with those in earlier studies. The pattern of significant predictors varied considerably depending on outcome measure--Hamilton depression score at discharge, global rating at discharge, or symptom score during a 6-month follow-up--which may explain some of the discrepancies between results of earlier predictor studies.