Schizophrenia spectrum disorders and autism spectrum disorder

Schizophrenia spectrum disorders (SSD) and autism spectrum disorder (ASD) are currently conceptualised as separate illnesses; however, this has not always been the case. The disorders share multiple phenotypic similarities and risk factors and have been reported to co-occur at elevated rates. In this chapter, we examine the level of comorbidity found between the disorders and the overlap between ASD and SSD at a clinical and trait level and discuss difficulties in the diagnosis and evaluation of the disorders. We then discuss genetic and neurobiological evidence, highlighting similarities and areas of distinction. Finally, we present treatment options, including non-medical and novel treatment strategies as well as pharmacological interventions.