Electroconvulsive therapy modulates brain functional stability in patients with major depressive disorder

Electroconvulsive therapy (ECT) is an effective treatment for patients with major depressive disorder (MDD), but the underlying neuromodulatory mechanisms remain largely unknown. Functional stability represents a newly developed method based on the dynamic functional connectivity framework. This study aimed to explore ECT-evoked changes in functional stability and their relationship with clinical outcomes.

We collected longitudinal resting-state fMRI data from 58 MDD patients (39 of whom experienced remission after ECT, and 19 did not, referred to as remitters and non-remitters, respectively) and 42 age- and sex-matched healthy controls. We utilized voxel-level whole-brain functional stability analysis to examine the neural effects of ECT in MDD patients.

After ECT, MDD patients showed increased functional stability in the bilateral middle frontal gyrus, orbital part, and bilateral angular gyrus as well as decreased functional stability in the right fusiform gyrus. Additionally, the subgroup analysis revealed that functional stability of the right hippocampus significantly decreased in remitters yet significantly increased in non-remitters after ECT.

Our data demonstrated the modulatory effect of ECT on brain functional stability in MDD patients and further revealed the differences in this modulation between patients with and without clinical remission, highlighting the potential usefulness of functional stability as a prognostic biomarker for monitoring ECT efficacy and stratifying MDD patients to optimize treatment strategies.