Brief and acute psychoses: the development of concepts.

This paper reviews the conceptual history of brief and acute psychoses. As psychotic disorders of usually dramatic symptomatology but nevertheless with a usually benign course, brief and acute psychoses have the air of a paradox. Thus, they have posed specific problems in regard to nosology, diagnostics and aetiology. Despite a strong convergence of the descriptive elements, the historical concepts of brief and acute psychoses have yielded different answers to the questions raised. Kahlbaum and Kraepelin set the stage on which brief and acute psychoses appeared "atypical". The concept of "bouffée délirante" used degeneration theory as a background for nosological and aetiological allocation. Similarly, the concepts of cycloid psychoses, reactive (psychogenic) psychoses, emotional psychoses and atypical psychoses have provided diverging but interrelated ways to delineate brief and acute psychoses, to determine their nosological status and to explain the coexistence of severe disorder and favourable prognosis. Modern classifications, namely the acute and transient psychotic disorder of ICD-10 and the brief psychotic disorder of DSM-IV, reflect the varied history of the concept.