William S. Stone, PhD;* Lisa Iguchi, PhD

Study Background: Schizophrenia and autism are both neurodevelopmental disorders that were once considered to be the same disorder expressed in different developmental periods. Although they were separated diagnostically about 40 years ago, they share several clinical and possibly, etiological features. This paper reviews overlaps in four domains of function to consider the issue of whether these similarities are sporadic and likely to represent superficial similarities, or whether the disorders are more likely to share some features in common. Methods: Representative areas of function were reviewed and compared for aspects of cognition (nonverbal reasoning, memory and language), social function (orienting / joint attention, eye contact and theory of mind), brain function (structural differences) and genetics. To facilitate comparisons with schizophrenia, a focus on high functioning autism / Asperger’s disorder was utilized, particularly in the sections on cognition and social function. Results: Significant similarities (and differences) characterized comparisons in each domain. Conclusions: Disturbed function in similar clinical (in cognition and social function), neurobiological (brain volumes) and genetic (e. g., involvement of the same genes or chromosomal locations) domains in autism and schizophrenia supports the hypothesis that while they are distinct disorders, they are not entirely unique. Additional studies of similarities and differences between them may thus shed light on common etiological mechanisms and hopefully, facilitate the development of novel treatment targets.

Key Words: Autistic spectrum disorder, cognition, social cognition, schizophrenia spectrum disorder Autistic spectrum disorder, cognition, social cognition, schizophrenia spectrum disorder

William S. Stone, PhD;^* Lisa Iguchi, PhD
Department of Psychiatry, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA
*Corresponding Author: Harvard Medical School, Department of Psychiatry/BIDMC, 401 Park Drive, 2nd Floor East, Boston, MA 02215. Tel: 617-998-5035 Fax: 617-998-5007. (Email: wstone@bidmc.harvard.edu)

CONFLICT OF INTEREST
None.

ACKNOWLEDGEMENTS
This work was supported in part by Ortho-McNeil Janssen Scientific Affairs, LLC, and by National Institute of Mental Health Grant RO1-MH065562 (COGS; Consortium on the Genetics of Schizophrenia).