Causal Interactions Between the Default Mode Network and Central Executive Network in Patients with Major Depression

Area of Science:

• Neuroscience
• Psychiatry
• Cognitive Science

Background:

• The human brain features interacting task-positive (central executive network - CEN) and task-negative (default mode network - DMN) systems.
• Previous research links both CEN and DMN to major depressive disorder (MDD), but causal interactions remain unclear.

Purpose of the Study:

• To investigate causal interactions between the CEN and DMN in individuals with MDD compared to healthy controls.
• To elucidate how these network dynamics contribute to the neural underpinnings of depression.

Main Methods:

• Resting-state fMRI data from 43 MDD patients and 56 healthy controls.
• Spectral dynamic causal modeling (spDCM) to analyze effective connectivity.
• Parametric empirical Bayes (PEB) model for group comparisons.

Main Results:

• Significant effective connectivity was observed between CEN and DMN regions in both groups.
• Inhibitory influences from CEN to DMN were detected, potentially explaining observed anticorrelations.
• MDD patients exhibited increased within-CEN connectivity and reduced CEN-to-DMN connectivity compared to controls.

Conclusions:

• MDD is associated with altered causal interactions between the CEN and DMN.
• Impaired top-down control of the DMN by the CEN may be a key feature of MDD.
• Findings offer novel insights into the neural basis of major depressive disorder.