The authors compared 65 patients with major depression and psychotic features to 192 patients with major depression and no psychotic features in terms of clinical features, family history, and hypothalamic-pituitary-adrenocortical axis function. In accord with other studies, patients with psychotic depression were more likely to have bipolar depression, psychomotor disturbance, a family history of schizophrenia, and a more severely disordered hypothalamic-pituitary-adrenocortical axis. Whether psychotic depression is best considered apart from nonpsychotic depression or as simply a more severe form of depression remains unsettled. Nevertheless, research to date does give the diagnosis of psychotic depression a practical significance which is enhanced by its simplicity.