The alteration of cognitive function networks in remitted patients with major depressive disorder: an independent component analysis.

Abstract Introduction Dysfunctional connectivity of resting-state functional networks has been observed in patients with major depressive disorder (MDD), particularly in cognitive function networks including the central executive network (CEN), default mode network (DMN) and salience network (SN). Findings from studies examining how aberrant functional connectivity (FC) changed after antidepressant treatment, however, have been inconsistent. Thus, the purpose of the present study was to explore potential mechanisms of altered cognitive function networks during resting-state between remitted major depressive disorder (rMDD) patients and healthy controls(HCs) and furthermore, the relationship between dysfunctional connectivity patterns in rMDD and clinical symptoms. Methodology In this study, 19 healthy controls (HCs) and 19 rMDD patients were recruited for resting-state functional magnetic resonance imaging (fMRI) scanning. Functional connectivity (FC) was evaluated with independent component analysis for the central executive network (CEN), default mode network (DMN) and salience network (SN). Two sample t tests were conducted to compare differences between rMDD and HCs. A Pearson correlation analysis was also performed to examine the relationship between connectivity of networks and cognitive function scores and clinical symptoms. Results Compared to healthy controls, remitted patients showed lower connectivity in CEN, mostly in the superior frontal gyrus (SFG), middle frontal gyrus (MFG), inferior parietal lobule (IPL) and part of the supramarginal gyrus (SMG). Conversely, the bilateral insula, part of the SMG (a key node of the CEN) and dorsal anterior cingulate cortex (dACC) of the DMN showed higher connectivity in rMDD patients. Pearson correlation results demonstrated that connectivity of the right IPL in CEN was positively correlated with cognitive function scores, and connectivity of the left insula was negatively correlated with BDI scores. Conclusions Though rMDD patients reached the standard of clinal remission, unique impairments of functional connectivity in cognitive function networks remained. Aberrant FC between cognitive function networks responsible for executive control was observed in rMDD and may be associated with residual clinical symptoms.