[The limits of depressive illness (author's transl)].

There are a number of issues relating to the classification of affective disorders. Although they are closely interconnected, they have been considered in isolation from each other. The main issues that arise in this field are the relationship of bipolar and unipolar disorders, the importance of autonomous and neurotic forms of depression, the boundaries between depressive and anxiety disorders and the relationship of schizoaffective and kindred conditions to affective disorders. When these issues, considered in the past in isolation, are examined together, certain problems of classification of disorders of affect and their treatment are clarified and a number of questions are posed for future enquiry.