Title : Disrupted topology of superior frontal gyrus in patients with remitted major depressive disorder and their siblings: Potential endophenotype of vulnerability?
Abstract:
Abnormalities in topological architecture of brain functional network have been extensively reported in major depressive disorder (MDD). However, it is unclear whether these abnormalities are also present in remitted MDD (rMDD) and their siblings, which may be crucial in revealing the endophenotype of MDD. The present study aims to characterize the topological alterations in patients with rMDD and their siblings. We investigated the topological architecture of functional network in sixty-seven patients with rMDD, 50 unaffected siblings of rMDD patients, and 63 healthy controls (HCs) by using graph theory and network-based statistics (NBS) analysis. Correlation analysis was also performed between network metrics and neuropsychological scores as assessed by clinical scales. Compared to the siblings and HCs, rMDD patients exhibited significantly decreased clustering coefficient and local efficiency (Eloc). Both rMDD patients and the siblings showed decreased degree centrality in the left superior frontal gyrus (SFG) compared to the HCs. NBS analysis revealed that rMDD patients exhibited significantly reduced connectivity between default mode network (DMN)-frontoparietal network (FPN), DMN-cingulo-opercular network (CON), and FPN-CON compared to HCs. In comparison to the siblings, rMDD patients showed reduced connectivity between DMN-CON, and FPN-CON. The correlation analysis revealed a negative correlation between Eloc and Stroop-C in the rMDD group and the DC of left SFG was negatively correlated with the random errors of Wisconsin Card Sorting Test. The finding of decreased DC of SFG may represent an endophenotype of vulnerability in MDD, and the remaining findings may be seen as scarring following prolonged disease states, which may aid in the identification of high-risk individuals for MDD and early intervention.
