The Comprehensive Assessment List for Affective Disorders (COALA): a polydiagnostic, comprehensive, and serial semistructured interview system for affective and related disorders

This supplement describes the development and structure of the Comprehensive Assessment List of Affective Disorders (COALA) system, which was recently developed for a collaborative follow-up study of a broad spectrum of affective disorders in Japan and which consists of a series of semistructured interviews for affective and related disorders. The COALA distinguishes itself from the extant semistructured interviews by being able to provide polydiagnostic, comprehensive and serial assessments. It is polydiagnostic because it derives diagnoses according to 29 historical and modern diagnostic systems through computer algorithms. It is comprehensive because it not only depicts the symptoms profile and rates their severity according to various endogenicity indices and severity rating scales but also measures, in the psychosocial domain, the life events and their characteristics. In addition, it has sections for past illnesses and family history. It is serial because the system includes follow-up semistructured interviews that can be administered monthly and that monitor changes in the psychopathological and psychosocial features. The theoretical underpinnings of the COALA system, especially its polydiagnostic approach to a broad spectrum of affective disorders and its treatment of psychosocial factors, are discussed in view of recent proposals for the future nosological research. The findings of the interrater reliability study (n = 107) are also presented, with satisfactory to excellent results for almost all of the psychopathological and psychosocial variables, all of the composite severity ratings and most of the polydiagnostic evaluations.