By combining regional homogeneity (ReHo) and functional connectivity (FC) analyses, this study aimed to explore brain functional alterations in Attenuated Psychosis Syndrome (APS), which could provide complementary information for the neurophysiological indicators for schizophrenia (SZ) associated brain dysfunction. Twenty-one APS subjects and twenty healthy controls were enrolled in the data acquisition of demographics and clinical characteristics as well as structural and resting-state functional magnetic resonance imaging (rs-fMRI). ReHo analysis was conducted to determine the peak coordinate of the abnormal regional brain activity. Then, identified brain regions were considered as seed regions and were used to calculate FC between reginal brain voxels and whole brain voxels. Finally, potential correlations between imaging indices and clinical data were also explored. Four APS and two HC subjects were excluded because the largest dynamic translation or rotation had exceeded 2 mm / 2°. Compared with healthy controls (HCs), APS subjects exhibited higher ReHo values in the right middle temporal gyrus (MTG) and lower ReHo values in the left middle frontal gyrus (MFG), left superior frontal gyrus (SFG), left postcentral gyrus (PoCG), and left superior frontal gyrus, medial (SFGmed). Considered these areas as seed regions, the APS subjects showed abnormal enhancement in functional brain connections, predominantly in the frontal and temporal lobes. We concluded that the APS subjects had spatially regional dysfunction and remoted synchronous dysfunction in the frontal and temporal lobes of the brain, and changes in ReHo and FC patterns may reveal the mechanism of brain dysfunctions and may serve as an imaging biomarker for the diagnosis and evaluation of SZ.

Background: Suicidal ideation (SI) is a major cause of death in patients with major depressive disorder (MDD). Although current clinical tools can assess suicide risk, objective neurobiological markers based on research remain lacking. Clinical evidence suggests that resting-state functional magnetic resonance imaging (rs-fMRI) studies utilizing voxel-mirrored homotopic connectivity (VMHC) analysis can uncover the neural mechanisms underlying mental disorders. This study explores differences in interhemispheric connectivity between MDD patients with and without SI, aiming to identify imaging biomarkers for suicide risk. Methods: This study included 48 SI patients and 44 non-SI patients. VMHC values were calculated to assess interhemispheric functional connectivity. Brain regions with significant differences between the groups were identified. A support vector machine (SVM) model was applied to evaluate the utility of VMHC values in distinguishing SI patients from non-SI patients with MDD. Results: Patients with suicidal ideation exhibited significantly increased VMHC values in the superior frontal gyrus, putamen, inferior temporal gyrus, and cerebellum compared to those without suicidal ideation. The SVM model achieved an accuracy of 77.2%, sensitivity of 83.3%, specificity of 70.5%, and an area under the curve (AUC) of 0.81. When combining VMHC values from multiple brain regions, classification accuracy improved to 86.8%. Conclusion: MDD patients with SI exhibit abnormal interhemispheric connectivity, with VMHC abnormalities in specific brain regions serving as potential biomarkers for suicide risk. The integration of machine learning and neuroimaging highlights the clinical relevance of VMHC as a tool for early detection and targeted intervention in suicide prevention.