Decreased voxel-mirrored homotopic connectivity in adolescent major depressive disorder with suicidal ideation.

Objective: Although altered brain activity is associated with suicidal ideation (SI) in adolescents with major depressive disorder (MDD), the status of inter-hemispheric connectivity remains elusive. This study aimed to investigate changes in resting-state interhemispheric functional connectivity in adolescents with MDD and SI.

Methods: A total of 45 adolescents with MDD and SI and 28 healthy controls (HCs) underwent comprehensive psychological assessments and MRI scans. Voxel-mirrored homotopic connectivity (VMHC) was compared between the two groups. We also performed correlation analyses between VMHC values of the affected brain regions and clinical characteristics.

Results: Compared to HCs, adolescents with MDD and SI showed decreased VMHC values in the bilateral angular gyri, bilateral insulae, bilateral middle occipital cortices, bilateral cerebellar regions and the right precuneus. No significant correlation was found between the VMHC values of affected brain regions and the clinical data in the adolescents with MDD and SI.

Conclusion: This study demonstrates decreased inter-hemispheric functional connectivity in multiple brain regions among adolescents with MDD and SI, suggesting potential disruptions in neural coordination between hemispheres. These results provide novel insights into the neurobiological mechanisms underlying SI in MDD, highlighting the potential role of impaired hemispheric integration in its pathophysiology.