Evolving Concepts of the Schizophrenia Spectrum: A Research Domain Criteria Perspective

Abstract

Several trends intersecting over the past two decades have generated increasing debate as to how the concepts of schizophrenia, the schizophrenia spectrum, and the psychotic disorders spectrum should be regarded. These trends are reflected in various areas of research such as genomics, neuroimaging, and data-driven computational studies of multiple response systems. Growing evidence suggests that schizophrenia represents a broad and heterogenous syndrome, rather than a specific disease entity, that is part of a multi-faceted psychosis spectrum. Progress in explicating these various developments has been hampered by the dependence upon sets of symptoms and signs for determining a diagnosis, and by the reliance on traditional diagnostic categories in reviewing clinical research grants. To address these concerns, the U.S. National Institute of Mental Health initiated the Research Domain Criteria (RDoC) project, a translational research program that calls for studies designed in terms of empirically-based functions (such as cognitive control or reward learning) rather than diagnostic groups. RDoC is a research framework rather than an alternative diagnostic system, intended to provide data that can inform future nosological manuals. This commentary includes a brief summary of RDoC as it pertains to schizophrenia and psychotic spectra, examples of recent data that highlight the utility of the approach, and conclusions regarding the implications for evolving conceptualizations of serious mental illness.

European Psychiatric Association guidance on assessment of cognitive impairment in schizophrenia

“…The construct of schizophrenia, even after about 110 years since its origin [1] and despite many modifications, has still made it into the contemporary classification systems, on the basis of which most of our evidence-based treatments have been clinically tested. However, although no paradigm shift has as yet happened in the classification of schizophrenia, research on transdiagnostic domain-specific deconstruction (Research Domains Criteria or RDoC) or reconstruction of hierarchical higher-order constructs (Hierarchical Taxonomy Of Psychopathology or HiTOP), including schizophrenia and other psychotic disorders, is fully underway [270][271][272][273].…”

Schizophrenia: A Narrative Review of Etiopathogenetic, Diagnostic and Treatment Aspects

“…Indeed, the traditional schizophrenia construct has elicited a continual debate as the concept has fluctuated across the years, according to the different psychopathological perspectives and the emerging advances in multiple areas of schizophrenia research (e.g., genomics, neuroimaging, epidemiology, and cognitive science) [ 72 ]. One of the major obstacles of the traditional schizophrenia construct regards the fact that disorders continue to be defined almost exclusively by a set of symptoms and signs, despite the association between the specific diagnostic categories and biological or behavioral measures having been proven to be modest or inconsistent, therefore, not allowing a better understanding of schizophrenia or the development of more effective interventions for the illness [ 73 ].…”

Development and environment in the National Institute of Mental Health (NIMH) Research Domain Criteria.

“…The apparent tendency for the field to latch onto more simplistic views of causation may-at least in part-be attributable to a tendency to equate clinical syndromes to disease entities. In any event, it is now clear that without the context of psychological and neural developmental processes in various pathways to mental illness, advances in treatments for psychopathology (whether traditionally-viewed child-onset or adult-onset disorders) are limited (Cuthbert & Morris, 2021). Zigler and Glick (1986), for instance, emphasized premorbid developmental processes to explain differences in course and outcome of paranoid and nonparanoid schizophrenia.…”