Background: In 1911 Bleuler's Dementia praecox oder Gruppe der Schizophrenien served to launch schizophrenia as a group of nosological entities characterized by a "splitting of the psychic functions." Today, at the centenary of this opus magnum, we find that the term is still in force but not the concept originally envisaged by Bleuler.
Method: For the sake of this conceptual analysis a literature search was carried out in PubMed, Embase, and the historical literature.
Results: The current schizophrenia concept, as operationalized in the DSM and other psychiatric classifications, is primarily indebted to Kraepelin and his degenerationist take on psychopathology. That approach is now obsolete, but the product still prevents us from moving beyond the notion of schizophrenia as a single-disease concept with multiple etiologies, multiple clinical expressions, and an unfavorable outcome.
Conclusions: If we aim to investigate the biological underpinnings of psychotic symptoms, first a deconstruction of the schizophrenia concept will need to take place. In this paper we highlight a method--called functionalization--which allows for such a deconstruction.
Limitations: Functionalization will probably require a new scientific language, which will be largely discontinuous with our current nosological and diagnostic systems.