摘要：Background and Aim: Recent magnetic resonance imaging (MRI) studies have revealed structural and functional differences in the human brain before and after an electroconvulsive therapy (ECT) series in patients with depression. The hippocampus is one of the well-documented subcortical areas that show an increase in cortical volume following an ECT series. Moreover, some resting-state functional MRI studies have shown that an ECT series alters the connectivities of the hippocampus with several brain areas. However, it remains unknown whether ECT can induce some sustained neurofunctional alterations in the human brain. Methods: In this study of the depressive patients with and without a history of modified ECT (N = 5 and 9, respectively) using a cross-sectional design, we investigated the functional connectivity between the left and right hippocampi in terms of blood-oxygenation-level dependent signal changes with time by resting-state functional MRI. Results: Voxel-based morphometry showed no significant structural differences in hippocampal volume between the ECT and non-ECT groups. The ECT group showed a significantly lower functional connectivity between the same brain areas than the non-ECT group (p < 0.01). Conclusions: Although their clinical significance remains unclear, our results suggest that an ECT series induces a sustained neurofunctional alteration in the human brain.
