Schizophrenia and autism spectrum disorder (ASD) are classified as distinct disorders; however, growing evidence suggests that they share genetic, neurobiological, and symptomatic features. Individuals with ASD have a higher risk of developing schizophrenia, and autistic symptoms frequently co-occur with schizophrenia spectrum disorder (SSD). Recently, a growing number of studies have been focusing on the association between autistic symptoms and clinical outcomes in patients with SSD, shifting the focus from categorical distinctions or overlaps between ASD and SSD to dimensional approaches. This narrative review examines the role of autistic symptoms in individuals with SSD, focusing on cognitive function, social functioning, psychosocial outcomes, neuroimaging findings, and treatment responsiveness. A literature search was conducted using PubMed, Web of Science, and Scopus to identify studies on autistic symptoms in SSD. Autistic symptoms in SSD are associated with cognitive deficits, and social functioning tends to be impaired in individuals with stronger autistic symptoms. Limited studies have suggested that autistic symptoms may influence treatment response in schizophrenia. We propose that autistic symptoms in SSD may manifest in three distinct patterns based on the severity of pre-onset autistic symptoms. Future studies should clarify whether these symptoms represent a distinct SSD subtype or share common neurodevelopmental mechanisms with ASD. • Autistic symptoms in SSD are associated with cognitive deficits. • Social functioning may be impaired in individuals with stronger autistic symptoms. • These symptoms are strongly associated with cognitive and social impairments. • Genetic and neuroimaging studies remain limited, obscuring underlying mechanisms.
Komatsu et al. (2026) studied this question.