Perspectives on depression-past, present, future

Depression presents a wide canvas for considering some approaches, issues, and problems in the study of major categories of mental illness in the context of current behavioral and molecular neurobiology. The study of depression encompasses multiple interactions among psychiatry, neurology, and neuroscience, as well as interactions with a host of other disciplines. This paper considers issues from an American perspective and discusses topics including historical aspects of the ways humanity has struggled with depression; the growth of approaches, and the ``wars'' in psychiatry in the middle of the 20th century between different ideologies; the development of psychiatry as a behavioral science inclusive of many disciplines; current diagnostic systems such as the Diagnostic and Statistical Manual of Mental Disorders (DSM-5) of the American Psychiatric Association, and the ICD-10 Classification of Mental and Behavioral Disorders of the World Health Organization; the efforts to delineate subtypes of depression; the search for new neurobiological and behavioral targets in the context of the National Institute of Mental Health's Research Domain Criteria framework; and examples of potential future discoveries and disciplines that may ultimately improve treatment.