The clinical spectrum of so-called "minor" depressions.

Reviewing the recent literature on the overlapping spectrum of neurotic depressive and dysthymic conditions--unofficially referred to as "minor," "atypical" or "characterologic" depressives--the authors conclude that significant symptomatologic admixtures with anxiety disorders do not represent the prototypical features of these disorders as defined in DSM-III-R. It is long-standing anhedonia on an intermittent or chronic basis which appears to characterize the trait illness of dysthymia. The emerging data on dysthymia suggest that it begins early in life, is often complicated by major depressions, and pursues a chronic--often pernicious--course. The development of hypomanic switches during the prospective course of some of these patients further suggests some kinship to bipolar disorder. Although traditionally conceived as being largely "psychogenic," familial data and selected biologic indices--especially in the area of sleep--and thymoleptic responsiveness impart some credibility to the role of biologic factors in the origin of these disorders. Given the high prevalence of dysthymic conditions in clinical practice, new research strategies on their causes are needed as a precondition for more rational treatment approaches.