On psychosis: Karl Jaspers and beyond

Abstract

Psychosis is one of the cardinal concepts of psychopathology (Jaspers), with an important descriptive use and frequent but unclear nosological connotations. Despite its central role in clinical psychiatry, it is only inadequately and vaguely addressed and articulated in the contemporary psychodiagnostic manuals. Typically, the descriptive use of this concept—as a ”break with reality”—is always infused with, and framed by pathogenetic hypotheses (e.g. ”weak ego-function” or ”brain disorder”). Because we are not in possession of any extraclinical index of psychosis, all definitions of”psychosis” and ”psychotic” remain on a vague, descriptive level and are often tautological. In particular, the attempts to define psychosis through the presence of delusions (or other ”psychotic symptoms”) only recapitulate the puzzle. This essay tries to identify a phenomenological commonality to such descriptions, examining the philosophical and clinical aspects of the concepts of”reality”, ”rationality” (theoretical and practical), ”reality testing”, ”intersubjectivity”, delusion, hallucination etc. It is concluded that ”psychosis” is a normative, context-sensitive, non-operationalizable concept, indicating a condition of ”radical irrationality”. This concept, although invaluable in clinical and legal work, is probably of only limited nosological (etiological) value.