The Changes of Functional Connectivity Strength in Electroconvulsive Therapy for Depression: A Longitudinal Study

Abstract

Electroconvulsive therapy (ECT) is an effective treatment for depression, but the mechanism of ECT for depression is still unclear. Recently, neuroimaging studies have reported that the prefrontal cortex, hippocampus, angular gyrus, insular and other brain regions are involved in the mechanism of ECT for depression, and these regions are highly overlapped with the location of brain hubs. Here, we try to explore the effects of ECT on the functional connectivity of brain hubs in depression patients. In current study, depression patients were assessed at three time points: prior to ECT, at the completion of ECT and about 1 month after the completion of ECT. At each time point, resting-state functional magnetic resonance imaging, assessment of clinical symptoms and cognition function were performed respectively, which was compared with 20 normal controls. Functional connectivity strength (FCS) was used to identify brain hubs. The results showed that FCS of left angular gyrus in depression patients significantly increased after ECT, accompanied by improved mood. The changed FCS in depression patients recovered obviously at 1 month after the completion of ECT. It suggested that ECT could modulate functional connectivity of left angular gyrus in depression patients.

Keywords: brain hub; depression; electroconvulsive therapy; fMRI; treatment.

FIGURE 1

(A) The scores of HAMD in each group. (B) The scores of MMSE in each group. (C) The scores of VF in each group. The clinical and cognitive outcome in normal controls and depression patients. NC, normal controls; TP1, patients at 12–24 h before the first ECT administration; TP2, patients at 24 h-1 week after the last ECT administration; TP2_p, patients at TP2 who completed the sacn of TP3; TP3, patients at about 1 month after the last ECT administration; HAMD, 17-item Hamilton Depression Rating Scale; MMSE, Mini mental state examination; VF, Verbal fluency. ^∗p < 0.05; ^∗∗p < 0.01.

FIGURE 2

(A) The stereogram of LAG. (B) The FCS value of LAG in each group. The Functional connectivity strength (FCS) values of left angular gyrus in normal controls and depression patients. NC, normal controls; TP1, patients at 12–24 h before the first ECT administration; TP2, patients at 24 h-1 week after the last ECT administration; TP2_p, patients at TP2 who completed the sacn of TP3; TP3, patients at about 1 month after the last ECT administration; LAG, left angular gyrus. ^∗p < 0.05; ^∗∗p < 0.01.