Nosology of primary affective disorders and application to clinical research.

The nosology of primary affective disorders is discussed with specific application of a six-stage model for clinical diagnosis utilizing an integrated nosological approach. The six phases of the clinical diagnostic model include: 1) Clinical description with delineation from other syndromes. 2) Physical and neurological factors. 3) Laboratory studies including psychological testing. 4) Family studies (pedigree studies). 5) Longitudinal--natural history studies. 6) Treatment outcome studies. Utilizing this six-stage model, the specific attributes of several major diagnostic systems for the affective disorders are compared and discussed. Specific operational diagnostic criteria described by Feighner et al., the Research Diagnostic Criteria by Spitzer et al., DSM-III, and ICD-9-CM are compared, and the merits of each are discussed. The nosological breakdown of the affective disorders with emphasis on the primary versus secondary axis and the unipolar versus bipolar axis is presented. In view of the ongoing development of more specific biological management of the affective disorders, it is imperative that systematic operational diagnostic criteria be utilized in current research to enhance homogeneity of research populations and to enhance communication between research centers.