[The Japanese version of the Calgary Depression Scale for Schizophrenics (JCDSS)]

Depressive features are clearly recognized within the context of schizophrenia, and clarification of the comorbidity has important clinical implications particularly when choosing the best neuroleptics for treatment. However, in some cases, it is difficult to clearly distinguish between depressive symptoms, negative symptoms and extrapyramidal side-effects. Conventionally, the Zung's Self-Rating Depression Scale or Hamilton's Depression Rating Scale has been used as an evaluation scale of depressive symptoms. However, as these scales are designed for assessment of depression in non-psychotic populations, they do not necessarily distinguish depressed from non-depressed psychotic subjects. Recently, Addington et al. developed a new depression scale, the Calgary Depression Scale for Schizophrenics(CDSS), which was designed for the assessment of depression in schizophrenia. CDSS is a nine item structured interview scale, in which each item has a four point measure, each point anchored by descriptors. It has been tested, and it has been shown that there is no overlap with negative or extrapyramidal symptoms. Therefore, for its clinical application, we prepared the Japanese-language version(JCDSS).