A comparative study of interhemispheric functional connectivity in major depression and schizophrenia

Area of Science:

• Neuroscience
• Psychiatry
• Radiology

Background:

• Major depressive disorder (MDD) and schizophrenia (SZ) are distinct psychiatric disorders with overlapping clinical and biological features.
• Prior research indicates abnormal interhemispheric functional connectivity (FC) in both MDD and SZ.
• Characterizing specific interhemispheric FC patterns in MDD and SZ is crucial for understanding their pathogenesis and differentiation.

Purpose of the Study:

• To investigate and compare patterns of interhemispheric functional connectivity (FC) in patients with MDD and SZ.
• To identify similarities and differences in FC between MDD, SZ, and healthy controls.

Main Methods:

• Recruited 36 patients each with MDD, SZ, and normal controls (NC).
• Utilized resting-state functional MRI (rs-fMRI) to acquire brain imaging data.
• Analyzed interhemispheric functional connectivity using voxel-mirrored homotopic connectivity (VMHC) and compared values via ANOVAs and post hoc tests.

Main Results:

• Significant differences in VMHC were found in the striatum and middle frontal gyrus (MFG) across the three groups.
• MDD patients showed reduced MFG VMHC compared to NC individuals.
• SZ patients exhibited increased striatum VMHC compared to both NC individuals and MDD patients.

Conclusions:

• The findings support the interhemispheric functional disconnection hypothesis in the pathogenesis of MDD and SZ.
• Distinct interhemispheric FC alterations in the MFG (MDD) and striatum (SZ) may provide a neuroimaging basis for differential diagnosis.