Global topology alteration of the brain functional network affects the 8-week antidepressant response in major depressive disorder.

Purpose: Previous studies have indicated that the global topology of the brain functional network in patients with major depressive disorder (MDD) differs from that of those with normal controls (NCs). However, the relationship between an altered global topology and the response to antidepressants remains unclear. Here, we investigated whether differences in global topology affect the efficacy of antidepressants in MDD patients.

Methods: 108 MDD patients and 61 NCs were recruited. A magnetic resonance imaging (MRI) scan was performed at the baseline, and the Hamilton Depression Scale-24 (HAMD-24) was assessed at baseline and after 2 and 8 weeks of antidepressant treatment. Seven global topological parameters of the brain functional network were measured and compared between groups. A correlation analysis was performed to identify the relationships between global topological parameters and antidepressant efficacy.

Results: The brain networks of MDD patients and NCs were both small-world networks. The clustering coefficient (C) and local efficiency (E) were significantly smaller in MDD patients compared with those in NCs. The characteristic path length (L) were negatively correlated with the 8-week reductive rate of HAMD-24 in the MDD group.

Conclusion: The present research found that the brain functional network of MDD patients still had a small-world organization but with a lower C and E than the NCs. In addition, the brain network global topology might have an impact on the antidepressant response and thus had the potential to become a treatment predictor of MDD.