Looking at the Schizophrenia Spectrum Through the Prism of Self-disorders: An Empirical Study

Abstract

Nonpsychotic anomalies of subjective experience were emphasized in both classic literature and phenomenological psychiatry as essential clinical features of schizophrenia. However, only in recent years, their topicality with respect to the construct validity of the concept of the schizophrenia spectrum has been explicitly acknowledged, mainly as a consequence of the increasing focus on early detection and prevention of psychosis. The current study tested the hypothesis of a specific aggregation of self-disorders (SDs, various anomalies of self-awareness) in schizophrenia-spectrum conditions, comparing different diagnostic groups; 305 subjects, previously assessed in the Copenhagen Schizophrenia Linkage Study, were grouped into 4 experimental samples, according to their Diagnostic and Statistical Manual of Mental Disorders (Third Edition Revised) main diagnosis: schizophrenia, (n = 29), schizotypal personality disorder (n = 61), other mental illness not belonging to the schizophrenia spectrum (n = 112), and no mental illness (n = 103). The effect of diagnostic grouping on the level of SDs was explored via general linear model and logistic regression. The diagnosis of schizophrenia and schizotypy predicted higher levels of SDs, and SDs scores were significantly different between spectrum and nonspectrum samples; the likelihood of experiencing SDs increased as well with the diagnostic severity. The findings support the assumption that SDs are a discriminant psychopathological feature of the schizophrenia spectrum and suggest their incorporation to strengthen its construct validity, with potential benefit for both early detection and pathogenetic research.

Premorbid self‐disorders and lifetime diagnosis in the schizophrenia spectrum: a prospective high‐risk study

“…11,12,27 In the Copenhagen Linkage Study, SDs distinguished healthy high-risk individuals who exhibited few schizotypal features from healthy high-risk subjects with no schizotypal features. 40 In sum, our results, in conjunction with other SD studies, strengthen the rationale for a further exploration of the SDs as a potentially core phenotype of schizophrenia-spectrum disorders and its predictive utility in the prodromal research. 17 …”

Basic Self-Disturbance Predicts Psychosis Onset in the Ultra High Risk for Psychosis "Prodromal" Population

“…Similar findings were evident when this data set was analyzed according to schizophrenia spectrum conditions, with self-disturbance being characteristic of schizophrenia spectrum conditions and levels of self-disturbance increasing with diagnostic severity (no mental illness, mental illness not in the schizophrenia spectrum, schizotypal personality disorder, and schizophrenia). 26 Other work provides further evidence that basic selfdisturbance is a central feature of the preonset phase of psychotic disorders, particularly of schizophrenia spectrum disorders. Davidsen 27 found that, although there was a difference in the kind and number of single features, disorders of self-experience were evident in all subjects in a clinical high-risk sample (N = 11).…”

Clinical Manifestations of Self-disorders in Schizophrenia Spectrum Conditions

“… Self-disorders hyper-aggregate in schizophrenia spectrum disorders but not in other mental disorders [39][40][41][42][43]  There is no statistical difference in the level of selfdisorders among patients with schizophrenia and patients with the schizotypal disorder [41,43]  Self-disorders differentiate between first-admitted cases with bipolar psychosis and schizophrenia [42] and self-disorders occur more frequently in residual schizophrenia than in remitted bipolar psychosis [44]  Self-disorders occur in genetically high-risk individuals [45]  Self-disorders are detectable in community samples of adolescent diagnosed as suffering from "at-risk mental state" [46] and in clinical samples of young adults at Clinical High Risk for psychosis [47]  Prospective studies indicate that self-disorders predict transition to psychosis in an Ultra-High Risk for psychosis sample [48] and that high baseline scores of self-disorders predict later transition to a schizophrenia spectrum diagnosis [49,50]  Positive correlations have been found between self-disorders and positive symptoms, negative symptoms, formal thought disorders, and perceptual disturbances, respectively [43]  Correlations have been found between selfdisorders and social dysfunction [51] and suicidality [52,53], respectively  No correlations have been found between selfdisorders and IQ or neurocognitive measures [43,54,55], except for impaired verbal memory [54]  Self-disorders have been found to be temporarily stable over a 5-year period [56] …”