Dysthymia and cyclothymia in psychiatric practice a century after Kraepelin.

Kraepelin had a modern vision of affective illness. He hypothesized that affective recurrences arose from enduring dispositions of depressive, cyclothymic, irritable, or 'manic' types. These dispositions appeared as 'temperaments' in English translations of his work. In the extreme, such temperamental gloominess or moodiness is today officially diagnosed as 'dysthymic' or 'cyclothymic'; irritable and hyperthymic (or manic) dispositions have not received official sanction in the contemporary psychiatric nomenclature. This paper reviews recent research which supports Kraepelin's theoretical framework regarding dysthymic and cyclothymic dispositions both as clinically relevant extreme forms of temperament and as precursors of major affective episodes. Compelling lines of evidence along epidemiologic, clinical-descriptive, familial-genetic, therapeutic, and follow-up perspectives are summarized for each disposition. Much of what in contemporary psychiatry is considered to be in the realm of subthreshold affective conditions, overlaps considerably with Kraepelin's concepts of the trait affective dispositions described herein. Most importantly, although Kraepelin's observations were based primarily on hospitalized, severely ill affective patients, his broad vision still guides us today for understanding etiology and instituting public health and preventive measures in major affective episodes.