Electroconvulsive Therapy Regulates the Interhemispheric Functional Connectivity of the Dorsomedial Prefrontal Cortex in Depressive Patients: Evidence from 2 Independent Samples

Abstract

Background: The dorsomedial prefrontal cortex (dmPFC) is considered a crucial node in emotional and cognitive processes. Voxel-mirrored homotopic connectivity (VMHC) is a validated methodology for investigating interhemispheric coordination. This study aims to elucidate the effects of electroconvulsive therapy (ECT) on the interhemispheric connectivity of the dmPFC in patients with depression, using VMHC as a measure of bilateral neural coordination.

Methods: Thirty-three patients with depression, screened at the University of Science and Technology of China (USTC), and thirty-five patients with depression, screened at Anhui Medical University (AHMU), were selected as the subjects of this study. VMHC was employed to investigate the effects of ECT on bilateral hemispheric functional connectivity. The Hamilton Depression Rating Scale (HAMD) was used to assess depressive symptoms, and the relationships between changes in HAMD scores and VMHC values were examined.

Results: Following ECT, the depressive symptoms of all participants decreased (p < 0.001). The VMHC values in the dmPFC were significantly increased in both groups after ECT (p < 0.01). No significant correlation was found between the increasing VMHC values in the dmPFC and the changes in HAMD scores in depressed patients (p > 0.05).

Conclusion: These results show that ECT regulates interhemispheric functional connectivity in depressed patients, and significantly increases the VMHC values in the dmPFC. Our findings may provide a useful method for optimizing the treatment of depression.

Fig. 1.

The HAMD scores of patients before and after ECT. *** p 0.001. Abbreviations: USTC, University of Science and Technology of China; AHMU, Anhui Medical University; ECT, electroconvulsive therapy; HAMD, Hamilton Depression Rating Scale.

Fig. 2.

Comparison of voxel t-value mapping of VMHC in the dmPFC before and after ECT in USTC group patients. The bar graph below the figure represents t-values. Abbreviations: VMHC, voxel-mirrored homotopic connectivity; dmPFC, dorsomedial prefrontal cortex; L, Left; R, Right.

Fig. 3.

Changes in the VMHC scores in the dmPFC of the depression patients before and after ECT. ** p 0.01; *** p 0.001. Abbreviations: USTC, University of Science and Technology of China; AHMU, Anhui Medical University; ECT, electroconvulsive therapy; HAMD, Hamilton Depression Rating Scale; VMHC, voxel-mirrored homotopic connectivity; dmPFC, dorsomedial prefrontal cortex.

Fig. 4.

Analysis of correlation. (A) The correlation between the change of VMHC values in the dmPFC and the change of HAMD score was examined using Pearson correlation analysis. (B) The correlation between the changes of VMHC values in the dmPFC and the number of ECT sessions was assessed using Spearman correlation analysis. Abbreviations: USTC, University of Science and Technology of China; AHMU, Anhui Medical University; ECT, electroconvulsive therapy; HAMD, Hamilton Depression Rating Scale; VMHC, voxel-mirrored homotopic connectivity.