Structural and functional brain abnormalities in children with schizotypal disorder: a pilot study.

Schizotypal disorder lies in the schizophrenia spectrum and is widely studied in adult populations. Schizotypal disorder in children (SDc) is less well described. This study examined brain morphological and functional connectivity abnormalities in SDc (12 SDc and 9 typically developing children), focusing on the default mode and executive control brain networks. Results indicated that SDc is associated with reduced grey matter volume (GMV) in superior and medial frontal gyri, and increased resting-state functional connectivity between the superior frontal gyrus and inferior parietal lobule, compared to typically developing children (cluster-level FWE-corrected p < 0.05). The brain structure abnormality (GMV in left superior frontal gyrus) was correlated with clinical symptoms in SDc (r = -0.66, p = 0.026) and functional connectivity abnormality was correlated with extra-dimensional shifting impairments in all participants (r = 0.62, p = 0.011), suggesting their contribution to the underlying mechanisms of clinical presentation. These preliminary results motivate further work to characterize the neural basis of SDc and its significance as a risk factor for later psychosis.