Subcallosal Cingulate Structural Connectivity Differs in Responders and Nonresponders to Electroconvulsive Therapy.

Area of Science:

• Neuroscience
• Neuroimaging
• Psychiatry

Background:

• Subcallosal cingulate (SCC) activity correlates with treatment response in major depressive disorder (MDD).
• Electroconvulsive therapy (ECT) serves as a model to investigate treatment mechanisms in MDD.

Purpose of the Study:

• To determine if pretreatment SCC structural connectivity with corticolimbic-striatal circuitry predicts therapeutic outcome in MDD.
• To examine changes in SCC connectivity patterns following ECT treatment.

Main Methods:

• Diffusion MRI scans were acquired from 43 MDD patients and 31 healthy controls before and after ECT.
• Probabilistic tractography estimated SCC structural connectivity with the ventral striatum (VS), anterior cingulate cortex (ACC), and medial prefrontal cortex (mPFC).

Main Results:

• Lower SCC-mPFC connectivity was observed in ECT responders compared to nonresponders and controls, both pre- and post-treatment.
• MDD patients showed decreased SCC-ACC connectivity versus controls, but this did not differentiate responders.
• Bilateral SCC-VS connectivity decreased with ECT, irrespective of treatment response.

Conclusions:

• Reduced pretreatment SCC-mPFC connectivity may serve as a potential biomarker for predicting ECT response in MDD patients.
• SCC-mPFC connectivity alterations are relevant for guiding treatment selection in major depressive disorder.