Marital therapists have an, as yet, unrecognized contribution to make to the treatment of depression. It is incumbent upon them to keep abreast of the growing literatures concerning both biological and interpersonal aspects of depression, and to inform other mental health professionals, policy makers, and depressed persons and their families as to what marital therapy has to offer. Consistent with this goal, this article provides an introductory overview of recent findings concerning the biology of depression, the relative merits of medication versus psychotherapy, and the complex relationships between marriage and depression. While there is considerable evidence that many depressions have a biological component and that medication is an efficacious way of providing symptomatic relief, this in no way contradicts findings concerning the efficacy of psychotherapy and the importance of the marital relationship in the outcome of a depressive episode.