Spousal bereavement is a common event in later life and, not infrequently, an important cause of psychiatric and medical morbidity. Depression (along with suicide), anxiety, substance abuse, and symptoms of "complicated" grief are among the more important psychiatric sequelae of spousal bereavement. They may represent, in part, forms of abnormal reaction to the stress of loss and the challenges of adaption to becoming widowed. This paper summarizes current knowledge about the clinical phenomenology of the psychiatric sequelae to late-life attachment bereavement, some of the hypothesized antecedents of abnormal stress response to bereavement, psychobiologic correlates of bereavement-related depression, and the long-term course (including preliminary evidence on response to treatment with psychotherapy and antidepressant medication).