Schedule of Events | Symposia

Functional neurobiological effects of electroconvulsive therapy versus transcranial magnetic stimulation in treatment resistant depression

Poster Session D - Monday, March 31, 2025, 8:00 – 10:00 am EDT, Back Bay Ballroom/Republic Ballroom

Pedro Silva¹ (phdasilva@mgh.harvard.edu), Asif Jamil¹, Maia Gersten¹, Samadrita Chowdhury¹, Shane Walsh¹, Guillermo Garibay¹, Tracy Barbour¹, Joan Camprodon¹; ¹Harvard Medical School and Massachusetts General Hospital

Right unilateral electroconvulsive therapy (RUL-ECT) and high-frequency repetitive transcranial magnetic stimulation (rTMS) are established antidepressant treatments with similar efficacy, though their mechanisms of action remain unclear. This study compared brain functional changes, measured by the amplitude of low-frequency fluctuations (ALFF) and fractional ALFF (fALFF), in patients with treatment-resistant depression (TRD) treated with RUL ECT versus left dorsolateral prefrontal cortex (lDLPFC) 10 Hz rTMS. The study also explored the relationship between brain functional changes induced by ECT or rTMS and clinical response. Forty TRD patients were recruited from Massachusetts General Hospital, with 18 undergoing ECT and 22 receiving rTMS. Depression severity was assessed using the Hamilton Depression Rating Scale (HAMD-17). FMRI data were preprocessed with fMRIprep (v. 24.1.1). ALFF and fALFF analyses were performed using in-house scripts. A flexible factorial design was used at the group level to examine ALFF and fALFF changes across time points and treatment groups. Multiple regression analyses investigated the relationship between ALFF/fALFF changes and clinical improvements. Multiple comparisons were corrected using the Threshold Free Cluster Enhancement (TFCE) method. Linear mixed model analysis did not show a significant interaction between treatment group and time. After rTMS, ALFF and fALFF increased in the middle cingulate and superior medial frontal gyrus. However, no significant association was found between ALFF or fALFF changes related to any treatment and HAMD-17 score changes. In summary, the results indicate that although clinical outcomes may be comparable, only rTMS is linked to functional changes, underscoring the idea that there are different antidepressant therapeutic strategies.

Topic Area: METHODS: Neuroimaging