Objectives: To study areas of shared brain structural abnormalities related to the social brain network.
Methods: In this study, we MRI scanned 34 adolescents with high-functioning ASD (HF-ASD), 36 with a first episode of psychosis (FEP), and 34 healthy controls. We compared volumes, cortical thickness, and surface area of a priori selected regions of interest associated with social cognition (amygdala, insula, pars opercularis, superior temporal region, and precuneus region). The effect of IQ in the studied regions was also acknowledged via correlating IQ with the dependent variables and using it as a convariate variable when appropriate.
Results: HF-ASD and FEP patients had smaller insular volumes than normal controls [mean difference in left insula: HF-ASD vs. controls 4.37 cc (p=0.036), psychosis vs. controls 6.39 cc, p=0.006; right insula: HF-ASD vs. controls 5.03 cc (p=0.006), psychosis vs. controls 5.19 cc, p=0.021), after correcting for intracranial volume and age. Mean precuneus volume was smaller in both patient groups, reaching statistical significance in the case of HF-ASD, compared with control subjects (p=0.035 and p=0.01 for left and right precuneus, respectively).
Conclusions: This study shows that the insula (considered an important multimodal area involved in high-order mental processes) and, to a lesser extent, the precuneus region (important for self-awareness, episodic memory, and social and other communication) are areas of abnormal structure common to psychosis and HF-ASD patients. Further studies are needed to determine whether these areas of common abnormality are specific to these disorders or are shared with other human mental disorders.
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See more of: Brain Structure & Function