Neuronal network mechanisms associated with depressive symptom improvement following electroconvulsive therapy

Akihiro Takamiya, Taishiro Kishimoto, Jinichi Hirano, Shiro Nishikata, Kyosuke Sawada, Shunya Kurokawa, Bun Yamagata, Toshiaki Kikuchi, Masaru Mimura

Research output: Contribution to journalArticlepeer-review

14 Citations (Scopus)


Background Electroconvulsive therapy (ECT) is the most effective antidepressant treatment for severe depression. Although recent structural magnetic resonance imaging (MRI) studies have consistently reported ECT-induced hippocampal volume increases, most studies did not find the association of the hippocampal volume changes with clinical improvement. To understand the underlying mechanisms of ECT action, we aimed to identify the longitudinal effects of ECT on hippocampal functional connectivity (FC) and their associations with clinical improvement. Methods Resting-state functional MRI was acquired before and after bilateral ECT in 27 depressed individuals. A priori hippocampal seed-based FC analysis and a data-driven multivoxel pattern analysis (MVPA) were conducted to investigate FC changes associated with clinical improvement. The statistical threshold was set at cluster-level false discovery rate-corrected p < 0.05. Results Depressive symptom improvement after ECT was positively associated with the change in the right hippocampus-ventromedial prefrontal cortex FC, and negatively associated with the right hippocampus-superior frontal gyrus FC. MVPA confirmed the results of hippocampal seed-based analyses and identified the following additional clusters associated with clinical improvement following ECT: the thalamus, the sensorimotor cortex, and the precuneus. Conclusions ECT-induced change in the right frontotemporal connectivity and thalamocortical connectivity, and changes in the nodes of the default mode network were associated with clinical improvement. Modulation of these networks may explain the underlying mechanisms by which ECT exert its potent and rapid antidepressant effect.

Original languageEnglish
Pages (from-to)2856-2863
Number of pages8
JournalPsychological Medicine
Issue number16
Publication statusPublished - 2021 Dec 1


  • electroconvulsive therapy
  • functional connectivity
  • functional magnetic resonance imaging
  • hippocampus
  • multivoxel pattern analysis

ASJC Scopus subject areas

  • Applied Psychology
  • Psychiatry and Mental health


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