Returning to the original problem of 'correcting' the earlier findings, it appears that it is not a question of who is right and who is wrong. Kraepelin outlined, and Angst clearly specified, the basic characteristics of the clinical course of unipolar and bipolar affective disorders which unfolds in patients without other pre-existing psychiatric disorders and which is typically episodic. The criteria for diagnosis applied not only cross-sectionally but also longitudinally. Recent studies, on the other hand, have put more emphasis on the standardized cross-sectional approach, and deal with a much broader population in which episodes of affective syndromes develop mainly on the basis of preexisting and chronic psychiatric disturbance, with more frequent recurrences and cycling. In a nutshell, Kraepelin and Angst provided us with a natural history of affective disorders whereas recent studies provide us with the clinical course of a broadly defined cluster of affective syndromes.