Are Self-disorders in Schizophrenia Expressive of a Unifying Disturbance of Subjectivity: A Factor Analytic Approach

BACKGROUND AND HYPOTHESIS: The idea that a disorder of the basic self is a central feature in schizophrenia has recently been corroborated in a meta-analysis and a systematic review. Manifestations of the self-disorder can be systematically explored with the Examination of Anomalous Self-Experience (EASE). In this study, we examined the factorial structure of EASE, and diagnostic efficacy of EASE. We hypothesized that EASE will have a monofactorial structure as an instability of the basic self will result in multiple deformations of self-experience which would be meaningfully interrelated as aspects of a unifying Gestalt. DESIGN: EASE data for 226 patients suffering from various mental disorders were analyzed under a confirmatory factor analysis framework (CFA). Area under the receiver operating characteristic curve (AUC) was calculated for the total EASE sums, and sensitivity and specificity values for prediction of schizophrenia spectrum disorders based on different cut-offs were obtained. RESULTS: Fit indices for the CFA model: RMSEA = 0.036, SRMR = 0.100, CFI = 0.983, TLI = 0.981. The AUC value was 0.946 (95% confidence interval: 0.919–0.974). Sensitivity as well as specificity for schizophrenia spectrum disorders were high. CONCLUSION: Our results lend support for EASE exhibiting a monofactorial structure and the notion of self-disorders as a central phenotypic feature of schizophrenia spectrum disorders.