Aberrant degree centrality profiles during rumination in major depressive disorder

Area of Science:

• Neuroscience
• Psychiatry
• Cognitive Psychology

Background:

• Rumination is a core feature of major depressive disorder (MDD).
• Previous neuroimaging studies linked trait rumination to functional brain coupling, but the neural mechanisms of active rumination in MDD remain unclear.
• Degree centrality (DC) measures network integration crucial for cognitive processes like rumination.

Purpose of the Study:

• To investigate the neural circuitry mechanisms underlying active rumination in individuals with MDD compared to healthy controls (HC).
• To examine the interaction between group (MDD vs. HC) and task condition (rumination vs. distraction) on brain activity using degree centrality.
• To explore the functional connectivity of identified brain regions and their relationship with affect.

Main Methods:

• Resting-state functional magnetic resonance imaging (MRI) was used.
• Participants included individuals with MDD (N=45) and HC (N=46) who underwent a rumination task during MRI.
• Vertex-wise degree centrality (DC) and seed-based functional connectivity (FC) analyses were performed, alongside functional characterization using Neurosynth and BrainMap.

Main Results:

• A significant interaction effect between group and condition was found in the left superior frontal gyrus (SFG), overlapping with the frontal eye field.
• The left SFG showed involvement in executive functions.
• Significant interaction effects were observed in functional connectivity (FC) between the left SFG and the frontoparietal and dorsal attention networks (DAN).

Conclusions:

• The left SFG is critically involved in the neural circuitry of rumination in MDD.
• Findings provide evidence for conceptualizing rumination in MDD as related to impaired executive control.
• The study highlights the role of the frontoparietal and DAN in the neural basis of rumination in MDD.