[The schizophrenia spectrum and other psychotic disorders in the DSM-5]

Abstract

Background: This article discusses changes made in the diagnostic criteria for psychotic disorders in the transition from DSM-IV to DSM-5.

Aim: To review and evaluate the changes incorporated in the DSM-5 criteria for psychotic disorders.

Method: Relevant documents and proceedings were reviewed on the basis of personal experience in the APA working group on psychotic disorders.

Results: The chapter on the 'schizophrenia spectrum and other psychotic disorders' in DSM-5 introduces a conceptual psychosis continuum, in which the level, number and duration of psychotic signs and symptoms are used to differentiate between various forms of psychotic disorders. The chapter includes only a few marginal adjustments, aimed at simplifying usage and measurement-based treatment. The DSM-5 Committee also aspired for harmonization with the ICD. The Committee was in favor of a new name for schizophrenia, but referred the matter to the WHO. The empirical basis for 'attentuated psychosis syndrome' was found to be insufficient for the syndrome to be included as a diagnosis. The most important changes in the criteria for schizophrenia are the elimination of the classic subtypes, the clarification of cross-sectional and longitudinal course specifiers, the elimination of special status of Schneiderian first-rank symptoms, and the clarification and better delineation of schizophrenia in terms of: a) the relationship between schizophrenia and schizoaffective disorders and b) the relationship between schizophrenia and catatonia. In schizoaffective disorder, the perspective shifts from an episode diagnosis in DSM-IV to a life course for the illness in DSM-5. Although the committee gave serious consideration to the inclusion of trans-diagnostic dimensions, these have not been included; a factor that precludes more personalised diagnoses, at least for the time being.

Conclusion: The limitations of the classic system of categorical diagnosis are widely acknowledged and serious consideration has been given to the abolition of this type of diagnosis or at least to the possibility of enriching it with a transdiagnostic focus on dimensions of psychopathology. These steps have not been taken in DSM-5 - for the consensus committees this is evidently still a bridge too far.