Regions with Altered Degree Centrality and Their Functional Connectivity in First-Episode Drug-Naïve Major Depressive...

The aim of this study was to identify regions with altered degrees of centrality (DC) and changes in their functional connectivity (FC) in first-episode drug-naïve major depressive disorder (FEDN-MDD) patients using resting-state functional magnetic resonance imaging (fMRI).

The study included 74 FEDN-MDD patients who met the study criteria and 41 healthy controls (HCs). All had undergone fMRI scanning in the resting condition. To evaluate differences between FEDN-MDD patients and HCs, we first compared the DC between the 2 groups. The DC regions with the most significant differences were then taken as seeds, and their FC was calculated.

Right posterior cingulum cortex (PCC.R), right precuneus (PCUN.R), and right putamen (PUT.R) all showed significantly different DC values (P < .001) between FEDN-MDD patients and HC groups, which helped in distinguishing these groups. The PUT.R in FEDN-MDD patients showed increased FC (P < .001) with the right inferior temporal gyrus and right inferior occipital gyrus compared to HC. Moreover, the PCUN.R in FEDN-MDD patients showed decreased FC (P < .001) with bilateral cerebellum crus I, left cerebellum crus II, bilateral orbital medial frontal gyrus, right superior medial frontal gyrus, left precuneus, left posterior cingulum cortex, right superior frontal gyrus, and PCC.R compared with the HC group. The P-values for cluster testing were .050, while for voxel testing they were .001.

These findings imply that PUT.R, PCUN.R, and PCC.R serve as the core brain net hub in FEDN-MDD patients, and their FC displays aberrant function. This may involve a specific psychiatric neuropathology associated with FEDN-MDD.