Substantial differences between schizotypal disorder (SD) and Asperger syndrome/autism spectrum disorder (AS/ASD) exist in the context of the basic self, according to results from a study published in Schizophrenia Bulletin.

Researchers conducted a cross-sectional study of 51 patients with AS/ASD (n=22) or SD (n=29). Study participants were enrolled from the Danish Center for Autism and were interviewed using the Examination of Anomalous Self-Experience scale and assessed with the Schedules for Clinical Assessment in Neuropsychiatry. Interviews were conducted in a semistructured format and emphasized the presence or absence of self-disorders. The self-disorder concept was based on accounts from patients with early schizophrenia and represents such trait-like changes at the basic level of self-awareness as a diminished or unstable sense of basic self.

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On analysis, the researchers found that after accounting for several variables, such as gender, years of education, and special needs school attendance, there was a distinct difference in existence or nonexistence of self-disorders between the 2 study groups. In addition, the team reported significantly increased levels of self-disorders in patients from the SD group. For example, of the items in the Interference With Activities section of the Schedules for Clinical Assessment in Neuropsychiatry, a significant number of both SD and AS/ASD group members responded “yes” for worrying and tension (97% vs 69%, P =.02); affected thinking, concentration, energy and interests (90% vs 36%, P <.001); and depressed mood (69% vs 23%, P =.002). Members of the SD group reported high levels of sleep disturbances (66%), experiences of disorder of thought and replacement of will (62%), and perceptual disorders (other than hallucinations; 52%), whereas none of these symptoms were reported by members of the AS/ASD group.

One key limitation of the study was the absence of diagnostic blinding.

“Our findings indicate crucial differences between [AS/ASD] and [SD] at the level of the basic self,” the researchers wrote. “A broader exploration of the being-in-the-world in ASD (ie, including clinical explorations of intersubjectivity and intentionality) would shed even further light on both similarities and differences between the 2 spectra,” they concluded.

Reference

Nilsson M, Arnfred S, Carlsson J, et al. Self-disorders in Asperger syndrome compared to schizotypal disorder: a clinical study [published online May 3, 2019]. Schizophr Bull. doi:10.1093/schbul/sbz036