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.
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.
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