Subgenual cingulate cortical activity predicts the efficacy of electroconvulsive therapy

Area of Science:

• Neuroscience
• Psychiatry
• Neuroimaging

Background:

• Electroconvulsive therapy (ECT) is a highly effective treatment for severe depression.
• The precise neurobiological mechanisms underlying ECT's antidepressant effects remain largely unknown.
• Understanding ECT's mechanism is crucial for developing targeted depression therapies.

Purpose of the Study:

• To investigate the neurobiological changes associated with ECT response in treatment-resistant depression.
• To explore the role of resting-state functional magnetic resonance imaging (rs-fMRI) in understanding ECT mechanisms.
• To identify potential biomarkers for ECT efficacy.

Main Methods:

• Longitudinal rs-fMRI scans were acquired from 16 patients with treatment-resistant depression and 10 healthy controls.
• Scans were performed at baseline, after the first ECT session, and after a full course of bifrontal ECT.
• Fractional amplitude of low-frequency fluctuations (fALFF) and seed-based functional connectivity were analyzed.

Main Results:

• Depressed patients showed higher baseline fALFF in the subcallosal cingulate cortex (SCC), which decreased with ECT.
• Baseline SCC fALFF levels predicted treatment response to ECT.
• ECT reduced SCC connectivity with the hippocampus, temporal pole, and ventromedial prefrontal cortex.

Conclusions:

• Antidepressant effects of ECT may be mediated by the downregulation of SCC activity and its functional connectivity.
• SCC activity and connectivity changes represent potential biomarkers for ECT treatment engagement.
• Findings offer insights for developing novel therapeutic strategies for treatment-resistant depression.