Blurred Edges: Evolving Concepts of Autism Spectrum Disorders and Schizophrenia

Background: Adolescents who have autistic features, such as social communication deficits, as well as disorganized thinking and bizarre behavior, present diagnostic challenges for clinicians as well as for researchers. Autism and schizophrenia are both neurodevelopmental disorders; they have an interconnected history that has diverged diagnostically, but retains many shared characteristics. Once conceptualized as a type of schizophrenia, autism has separated into a distinct disorder, yet similarities are evident between the two. Recent research has called into question the complete dichotomous separation of these two disorders. Methods: This review covers the history, as well as the shared phenotypic and genotypic characteristics of the disorders, including genetics, imaging, language development, and social functioning. We present possible theoretical constructs to frame the nature and extent of the overlap given the available research. Results: Adolescents who have childhood histories consistent with autistic spectrum disorders can present with psychotic symptoms in adolescence. Conversely, adolescents who appear to have childhood or adolescent onset schizophrenia may also show autistic features. Various hypotheses have been proposed to explain the overlap between these two heterogeneous conditions. Conclusions: We believe that the overlaps between autism and schizophrenia represent an important and rich area of research in order to better understand the unique characteristics of each disorder that may help to aid understand mechanisms of development, refine models of prediction and risk, as well as to understand common characteristics that may help shape entry points for future intervention.