Developmental vulnerability to psychosis: Selective aggregation of basic self-disturbance in early onset schizophrenia.

Trait-like anomalies of subjective experience (aka, Basic Self-disturbance or Self-disorder, SD) have been empirically identified as schizophrenia-specific markers of vulnerability in several clinical and genetic high-risk populations. However, such specificity is still to be tested in developmental years, where emerging psychopathology is less crystallized and diagnostic boundaries more blurred. Thus, the current study explores the distribution of SD in adolescent help-seekers (age range 14 to 18) and tests the specificity of SD with respect to the severity of their diagnostic staging (Early Onset schizophrenia-spectrum psychosis [EOP], ultra high-risk [UHR] and clinical help-seeking controls [CHSC]). For this purpose, 96 help-seeking adolescents consecutively referred to specialized Child and Adolescent Units for diagnostic evaluation, underwent a comprehensive psychopathological examination including the specific interview for SD (i.e. the Examination of Anomalous Self-Experience, EASE). One-way ANOVA was used to test the diagnostic distribution of SD (EASE score), whereas multinomial logistic regression was used to test the effect of SD on the diagnostic outcome. SD frequency (both in terms of EASE total score and domain sub-scores) was decreasing progressively from EOP to CHSC, with intermediate levels in UHR. The EASE total score increased the risk of belonging to the more severe diagnostic stages (i.e, UHR and EOP vs CHSC as reference class) and allowed the correct reclassification of the 75% of the sample. The results confirm the schizophrenia-spectrum specificity of SD in adolescence, highlighting their potential value for early differential diagnosis and risk stratification.