In this article, we clarify, expand and revise the basic postulates of the hopelessness theory of depression (Abramson, Alloy & Metalsky, 1988a; Abramson, Metalsky & Alloy, 1987, 1988b; previously referred to as the reformulated helplessness theory of depression: Abramson, Seligman & Teasdale, 1978) and place the theory more explicitly in the context of work in descriptive psychiatry about the heterogeneity among the depressive disorders. We suggest that the hopelessness theory hypothesizes the existence in nature of an, as yet, unidentified subtype of depression’- ‘hopelessness depression’ - defined, in part, by its cause. We then give a critique of work conducted to test the hopelessness theory and explicate the limitations in research strategy associated with this line of work. Our critique includes a logical analysis that deduces the conceptual and methodological inadequacies of the research strategies used to test the theory. Finally, we suggest more adequate research strategies for testing the hopelessness theory and discuss conceptual and assessment issues that will arise in conducting such tests with special emphasis on attributional styles.