Electroconvulsive therapy modulates grey matter increase in a hub of an affect processing network

Area of Science:

• Neuroscience
• Psychiatry
• Radiology

Background:

• Recent studies suggest electroconvulsive therapy (ECT) induces neuroplastic changes detectable as alterations in regional gray matter volume (GMV).
• Recruiting sufficient patients for neuroimaging studies on ECT is challenging, leading to small sample sizes in most existing research.

Purpose of the Study:

• To investigate structural brain changes, specifically gray matter volume (GMV), in patients undergoing electroconvulsive therapy (ECT).
• To identify brain regions affected by ECT and their functional roles, potentially elucidating ECT's antidepressant mechanisms.

Main Methods:

• A multi-site, whole-brain voxel-based morphometry (VBM) analysis was conducted on 85 patients with unipolar depression before and after ECT.
• Structural differences were compared between patients and 86 healthy controls.
• Functional connectivity and characterization of identified regions were performed using healthy subject data and the BrainMap database.

Main Results:

• A significant increase in GMV was observed in the right hippocampus/amygdala region in patients post-ECT compared to controls.
• This region is functionally associated with emotional processing and memory networks.
• A decrease in GMV was noted in the left fusiform gyrus in patients at baseline compared to controls, with minor changes after ECT.

Conclusions:

• Electroconvulsive therapy (ECT) is associated with increased GMV in key emotion processing and memory-related brain regions.
• These neuroplastic changes in the hippocampus/amygdala may represent a plausible mechanism underlying ECT's efficacy in treating unipolar depression and other affective disorders.