Large MRI study finds regional brain asymmetry differences in schizophrenia

Researchers analyzed T1-weighted MRI scans from 1,761 individuals with schizophrenia and 1,513 healthy controls, primarily of East Asian ancestry. Using a standardized pipeline, they measured asymmetry in cortical thickness, surface area and subcortical volume. They also compared findings across two neuroanatomical subtypes previously identified using the Subtype and Stage Inference machine-learning algorithm.

Compared with controls, participants with schizophrenia had reduced leftward asymmetry in the rostral middle frontal gyrus, reduced rightward asymmetry in the medial orbitofrontal cortex and increased rightward asymmetry in the amygdala; all differences met Bonferroni-corrected significance thresholds (p<0.001). Subtype differences were observed in temporal and parietal regions, the precentral gyrus and caudate. Anterior cingulate volume asymmetry also showed differing correlations with negative symptoms across subtypes.

The authors report that case-control effects were small. Comparison with findings from Western cohorts comprising more than 5,000 people with schizophrenia showed only moderate similarity for cortical surface-area asymmetry (r=0.36), with no significant correlations for cortical thickness or subcortical volume. The findings support further investigation of subtype and ancestry effects, but do not establish diagnostic or treatment applications. The study was observational and relied primarily on East Asian participants.