Basic Self-Disturbances beyond Schizophrenia: Discrepancies and Affinities in Panic Disorder - An Empirical Clinical Study

Background: Anomalous self-experiences (ASEs), presumably involving alterations in "core" or "minimal self," have been studied as manifest in schizophrenia and its spectrum, in contrast with mood disorder and personality disorder samples. This is the first study to examine ASEs in panic disorder (PD), beginning the exploration of these disturbances of subjectivity in anxiety disorders. We aimed to clarify what might, or might not, be specific to the schizophrenia spectrum domain-which, in turn, could be useful for developing pathogenetic models for various disorders. Sampling and Methods: 47 hospital outpatients with PD and no other medical and psychiatric comorbidity and 47 healthy control (HC) subjects were assessed with the Examination of Anomalous Self Experiences (EASE) and Cambridge Depersonalization Scale (CDS). Results: All our PD patients had overall ASE and EASE scores significantly higher than our HCs (mean +/- SD 17.94 +/- 11.88 vs. HC 1.00 +/- 1.81), approaching levels found in previous schizophrenia spectrum samples. The distribution of particular EASE items and subitems in the PD sample was heterogeneous, varying from rare (< 10%) or absent (termed "discrepancies" with schizophrenia spectrum: 29 items) to being present in >50% of subjects ("affinities" with schizophrenia spectrum: 7 items). EASE and CDS scores were highly correlated (r = 0.756, 95% CI 0.665-0.840). Conclusions : PD patients scored higher on items suggesting common forms of derealization and depersonalization, perhaps suggesting "secondary" and defensive psychological processes, while lacking indicators of more profound ipseity disturbance. Our study supports the basic-self-disturbance model of schizophrenia, while suggesting the possibility of transnosological "schizophrenia-like phenomena," which might require careful phenomenological exploration to be distinguished from those of true psychotic or schizophrenic conditions.