Autism spectrum disorder and schizophrenia share a substantial number of
etiologic and phenotypic characteristics. Still, no direct comparison of both
disorders has been performed to identify differences and commonalities in
brain structure. In this voxel based morphometry study, 34 patients with
autism spectrum disorder, 21 patients with schizophrenia and 26 typically
developed control subjects were included to identify global and regional brain
volume alterations. No global gray matter or white matter differences were
found between groups. In regional data, patients with autism spectrum disorder
compared to typically developed control subjects showed smaller gray matter
volume in the amygdala, insula, and anterior medial prefrontal cortex.
Compared to patients with schizophrenia, patients with autism spectrum
disorder displayed smaller gray matter volume in the left insula. Disorder
specific positive correlations were found between mentalizing ability and left
amygdala volume in autism spectrum disorder, and hallucinatory behavior and
insula volume in schizophrenia. Results suggest the involvement of social
brain areas in both disorders. Further studies are needed to replicate these
findings and to quantify the amount of distinct and overlapping neural
correlates in autism spectrum disorder and schizophrenia
