Heterogeneous alterations in thalamic subfields in major depression disorder

Area of Science:

• Neuroimaging
• Neuroscience
• Psychiatry

Background:

• The thalamus, a complex brain structure, is implicated in major depressive disorder (MDD).
• Previous studies show thalamic alterations in MDD, but subfield-specific changes remain unclear.
• This study investigates gray matter volume (GMV) changes in thalamic subfields in MDD patients.

Purpose of the Study:

• To investigate structural alterations in thalamic subfields in major depressive disorder (MDD).
• To compare GMV differences in thalamic subfields between first-episode drug-naïve MDD (FEDN), recurrent MDD (RMDD), and normal controls (NC).
• To explore relationships between thalamic GMV and clinical symptoms in MDD.

Main Methods:

• Voxel-based morphometric analysis of structural MRI data from 848 MDD patients and 794 NCs.
• Comparison of GMV in the entire thalamus and subfields across FEDN, RMDD, and NC groups.
• Utilized three automated anatomical labeling atlases for subfield segmentation.

Main Results:

• FEDN patients exhibited increased GMV in specific thalamic subfields compared to NC.
• No significant GMV alterations were found in the entire thalamus or subfields for RMDD patients.
• Mild positive correlations observed between right anterior and left anteroventral thalamic GMV and anxiety scores in RMDD patients.

Conclusions:

• Findings suggest heterogeneous structural alterations in thalamic subfields between FEDN and RMDD.
• These subfield-specific changes may contribute to understanding MDD's pathophysiology.
• Limitations include a single-modal analysis and cross-sectional design.