Background: The goal of this study was to explore the notion that anomalies of self-experience (ASE) are a core, 'not-yet-psychotic' clinical phenotype of emerging schizophrenia and its spectrum. Method To accomplish this goal, we examined the relationship between ASE and commonly accepted risk markers in a sample of 87 help-seeking, non-psychotic adolescents (aged 14-18 years). ASE were assessed with the Examination of Anomalous Self-Experience (EASE), subclinical psychotic symptoms were assessed with the Prodromal Questionnaire and the Structured Interview for Prodromal Syndromes, deterioration in psychosocial functioning was assessed with the Social and Role Functioning Scales, and level of distress with the Mood and Anxiety Symptoms Questionnaire.
Results: About 82 participants completed the entire EASE interview. The number of participants who reported ASE at a clinically meaningful level (n = 18, 22%) was smaller than that who met diagnostic criteria for a prodromal syndrome (n = 28, 34%). The degree of overlap between the two conditions was moderate but statistically significant (χ2 (1) = 7.01, p = 0.008). An exploratory factor analysis revealed that ASE load on a different factor than prodromal symptoms and deterioration in functioning, but that there is a moderate correlation between the three factors.
Conclusions: These results suggest that ASE are prevalent among non-psychotic help-seeking adolescents, yet at a considerably lower rate than prodromal symptoms. In addition, they suggest that ASE and prodromal symptoms constitute distinct but moderately related dimensions of potential risk. Taken together, they provide preliminary support for the clinical usefulness of supplementing and refining the methods of early detection of risk with assessment of ASE.