[Classification of mood disorders: from the viewpoint of clinical psychiatry]

Various classifications of depression have been developed up to this time. They are divided into three categories--etiological, phenomenological and multidimensional classification. The author discussed characteristics of three classifications from the viewpoint of clinical psychiatry. Etiological classifications include Kielholz's one and Pichot's one. They are useful to guide to clinical practice, but clinical features are not clearly described in them. Phenomenological classifications include ICD-10 and DSM-IV. They are practical to facilitate research and improve communication among clinicians and researchers all over the world. Although their reliability is on the increase, they leave something to be desired in regard to pursuit of etiology. The most famous multidimensional classification in Japan is Kasahara and Kimura's one. It introduces multiaxial system that includes premorbid character, precipitating factor, clinical features, response to treatment, and course. However, it is not fully grounded in empirical evidence.