[Present nosology of the affective disorders (author's transl)].

The present nosology of the affective disorders seems accurate enough to enable valid definitions and classifications to be made, despite the differences between the countries and the methods of approach. Nevertheless, there has been much controversy regarding different clinical types, similar or opposite, and notably about whether the pathogenesis and etiology are single multiple. Consideration must be given not only to the clinical form presenting but also to the course (episodic, recurrent or chronic) and to the circadian variations. Moreover, it is absolutely essential to distinguish in the nosology, on the one hand, the clinical picture proper and, on the other hand, the aetiology or the psychic structure. Thus, a simple depression may be related to an endogenous process and a melancholic state may be reactive. The theoretical problems of classification may justify the use of multivariate analysis. However, it is doubtful whether sophisticated methods are absolutely necessary in clinical practice.