“Schizophrenia, Consciousness, and the Self” Twenty Years Later: Revisiting the Ipseity-Disturbance Model and the Developmental Nature of Self-Disorder in the Schizophrenia Spectrum

Self-disorders (SD) designate a pattern of non-psychotic anomalous self-experiences, which specifically aggregate in clinical and subclinical forms of schizophrenia spectrum disorders (SSD), including familial high-risk configurations. SD have been corroborated as a valuable, quantitatively tractable, trait phenotype for indexing genetic liability to SSD, and, as a risk phenotype, they offer critical insights into the nature of these complex conditions which precede and shape the development of more overt clinical manifestations (including schizotypal features and positive, negative, and disorganized symptoms). In the last three decades, the concept of self-disorders has evolved from early clinical observations to a well-defined research domain, offering a nuanced understanding of schizophrenia spectrum vulnerabilities and holding promise for improving diagnostic accuracy, enhancing prognostic assessments, offering novel targets for intervention, and advancing our understanding of the schizophrenia spectrum.