Reference Work Entry

Comprehensive Guide to Autism

pp 1645-1662

Autism and Schizophrenia: Genetic and Phenotypic Relationships

  • Jacob A. S. VorstmanAffiliated withDepartment of Psychiatry, Brain Center Rudolf Magnus, University Medical Center Utrecht
  • , J. Peter H. BurbachAffiliated withDepartment of Neuroscience and Pharmacology, Brain Center Rudolf Magnus, University Medical Center Utrecht Email author 


The diagnostic concepts of schizophrenia and autism are historically intertwined. A hundred years ago, the term autism was used in reference to the tendency of schizophrenic patients to create and live in a world of their own. In the 1940s after Kanner’s seminal paper, accounts of cases of infantile autism were described that demonstrated a significant resemblance to symptoms in schizophrenia. Up until the early 1970s, the standpoint that infantile autism could be considered as the early manifestation of childhood schizophrenia was prevalent. From then on, distinctions were made between autism and schizophrenia psychosis, despite commonalities in the clinical phenotypes. In recent years, a plethora of potential causative genes for autism and schizophrenia have been identified. Interestingly, a substantial number of these susceptibility genes (estimated 15–25 %) appear to increase the risk for both autism and schizophrenia. This observation has sparked a renewed discussion on the possible relatedness of both disorders. It revives issues such as shared and distinct phenotypic manifestations, possible common etiological mechanisms explaining the observed overlaps, and the relevance to the understanding of the biological pathways involved in autism and schizophrenia.