Transdiagnostic conceptualization of schizophrenia and autism spectrum disorder. An integrative framework of minimal self disturbance.

Aims: Autism spectrum disorder and schizophrenia are traditionally viewed as distinct diagnostic categories. However, evidence increasingly suggests overlapping pathological functioning at various levels, starting from brain circuitry to behaviour. Notably, both disorders are characterized by anomalous minimal self-experience (altered body ownership and agency), which is a trait-like, phenomenological distortion. We propose a conceptual framework that unites multiple levels, from neural mechanisms to cognitive and phenomenological correlates, for understanding minimal self-disturbance across diagnostic boundaries.

Methods: A comprehensive review of existing literature was conducted, examining phenomenological, neurocognitive, and neural correlates of minimal self-disturbance in both schizophrenia and autism spectrum disorder. Assessment tools and scales such as the Examination of Anomalous Self-Experience Scale, as well as experimental neurocognitive paradigms like the Rubber-Hand Illusion and self-relevant stimuli tasks, were examined for their relevance in evaluating self-experience in both conditions.

Results: Minimal self-disturbances were found to be a prominent feature of both schizophrenia and autism, albeit with different manifestations. Patients with schizophrenia showed heightened susceptibility to body ownership alterations, while individuals with autism exhibited decreased susceptibility. Neural markers, particularly within the default mode network and thalamocortical connectivity, were implicated in self-disturbance in both disorders, suggesting a shared neurobiological basis.

Conclusion: The minimal self- disturbance appears to be a transdiagnostic feature of both schizophrenia and autism spectrum disorder, indicating that these conditions may represent points along a shared psychopathological continuum. The proposed model integrates neurobiological, cognitive, and phenomenological aspects of self-disturbance, offering a comprehensive framework for understanding and assessing disruptions in self-experience across these conditions. This approach promotes a shift away from rigid diagnostic classifications towards approaches that highlight the importance of atypical self-experience. (Neuropsychopharmacol Hung 2024; 26(4): 218-226)