Psychotic Continuum Under Longitudinal Considerations

Abstract

The debate concerning the controversy of psychotic continuum, or “unitary psychosis,” and separate entities is as old as scientific psychiatry itself (Berrios and Beer 1992; Schmidt-Degenhardt 1992; Vliegen 1980). Distinguished psychiatrists in Germany, France, Great Britain, and other European countries supported the idea of unitary psychosis or of a universal pathogenesis of psychoses while other authors supported the idea of independent entities (Vliegen 1980). At the end of the nineteenth and, mainly, the beginning of the twentieth century, however separate entities had become widely accepted. The well-established system known worldwide following the idea of separate entities is Kraepelin’s dichotomy of functional disorders in dementia praecox (later schizophrenia) and manic-depressive illness (Kraepelin 1883-1920). Even more consequently than Kraepelin Wernicke (1900), Kleist (1928, 1953) and Leonard (1957, 1980) followed the idea of separate entities in psychiatry. In his Aufteilung der Endogenen Psychosen (Classification of Endogenous Psychoses) Leonard (1957) presented a taxonomy, like his teacher Kleist, of endogenous psychoses with a lot of groups and subgroups. Such a plethora of disease entities, in spite of some fruitful ideas, is connected with a lot of problems. Even followers, or part followers, of that concept found in empirical work that the boundaries between some of Leonard’s diseases (for instance, among the various subtypes of the “cycloid psychoses”) are very unclear (Perris and Brockington 1981).