Historical and conceptual features of acute polymorphic psychosis: a myth of European psychiatry from bouffée délirante to ICD-11 acute and transient psychotic disorder.

This article examines the history and epistemology of acute polymorphic psychosis through a comparative study of short-lived psychotic disorders across European psychiatric traditions since the late nineteenth century. It traces the evolution of key concepts such as bouffée délirante, cycloid psychosis, reactive psychosis, and schizophreniform psychosis, highlighting their varied clinical features, diagnostic challenges, and shifting theoretical frameworks, including the decline of the degeneration theory and the rise of symptom-based classifications. The paper discusses how these disorders have been incorporated into modern psychiatric classifications, notably the International Classification of Diseases (ICD) and the Diagnostic and Statistical Manual of Mental Disorders (DSM), where acute polymorphic psychotic disorder (listed under acute and transient psychotic disorders, ATPDs, in ICD-10 and ICD-11) and brief psychotic disorder (BPD in DSM-5) represent contemporary categories with overlapping but not identical criteria. The study concludes that despite terminological and conceptual differences, these short-lived psychoses share common features—acute onset, polymorphic symptoms, and rapid remission—and that polymorphic psychotic disorder serves as a prototype for acute transient psychoses, while earlier nosological concepts differ from current diagnostic categories.