Age-dependent gray matter volume alterations in healthy siblings of schizophrenia patients: a structural magnetic resonance imaging study

pairwise comparisons (Bonferroni-corrected) showed that PASW-SIB were significantly older than both SCZ (p < 0.001) and HCs (p < 0.001). sMRI data were processed using voxel-based morphometry (VBM8), and inter-group GMV comparisons were performed with one-way ANOVA and two-sample t-tests. Results showed no significant differences in demographic characteristics among the three groups (all p>0.05). One-way ANOVA revealed significant main effects of group on GMV in brain regions including the caudate nucleus, pallidum, insula, parahippocampal gyrus, and precuneus (F = 1.28-1.96, all p<0.01). Pairwise comparisons indicated that compared with HCs, PASW-SIB exhibited significantly increased GMV in the caudate nucleus, pallidum, and insula (all p<0.05, FDR-corrected), while ASW-SIB only showed reduced GMV in the parahippocampal gyrus and precuneus (all p<0.05, FDR-corrected). In contrast, SCZ patients exhibited reduced GMV in multiple regions (inferior temporal gyrus, superior frontal gyrus, postcentral gyrus, and insula) compared to HCs (all p < 0.05, FDR-corrected). No significant correlations were found between GMV and clinical symptoms (PANSS scores) or disease duration in SCZ patients (all p>0.05). These findings suggest age-associated GMV differences in healthy siblings of SCZ patients: PASW-SIB show widespread GMV alterations in the basal ganglia and insula, while ASW-SIB exhibit localized GMV differences in the default mode network. The age-specific neurostructural patterns are consistent with potential risk-related brain phenotypes for SCZ, which may provide imaging targets for future studies of early risk stratification and intervention in high-risk populations.