Disentangling the functional neurobiological effects of electroconvulsive therapy in major depression disorder: a resting-state functional MRI study

• Grant number: 23/13893-5
• Support Opportunities: Scholarships abroad - Research Internship - Post-doctor
• Start date: May 01, 2024
• End date: April 30, 2025
• Field of knowledge: Health Sciences - Medicine - Psychiatry
• Principal Investigator: Andre Russowsky Brunoni
• Grantee: Pedro Henrique Rodrigues da Silva
• Supervisor: Joan Camprodon
• Host Institution: Hospital Universitário (HU). Universidade de São Paulo (USP). São Paulo , SP, Brazil
• Institution abroad: Harvard University, Boston, United States
• Associated to the scholarship: 22/03266-0 - Investigation of neuroimaging assessments and current flow modeling as target engagement and predictor biomarkers of convulsive therapies, BP.PD

Abstract

Electroconvulsive therapy (ECT) is the most effective treatment for major depression disorder (MDD), even when compared to simulated ECT, repetitive transcranial magnetic stimulation (rTMS) and pharmacotherapy, the first line treatment for MDD. Although its clinical effects are well known, its neurobiological mechanisms underpinning the striking antidepressant effects remain poorly elucidated. More than that, a challenging question is if there is a single circuit-level therapeutic mechanism out of depression, or else there are different technique-specific paths towards euthymia. The comparison between the whole-brain volumetric changes in MDD patients treated with right unilateral ECT or left dorsolateral prefrontal cortex rTMS, as well as the association between volumetric changes and clinical response showed that may there are many therapeutic strategies to treat depression patients. When considering only the ECT sample and a dimensional and circuit-focused approach to evaluate the relationship between ECT-induced brain volumetric changes and improvement in anhedonia and overall depression severity, the findings pointed out the need to transitioning from a syndromal to a dimensional approach to investigate circuit-based neuromodulation treatments. However, the findings were based on only brain structural data. Studies have demonstrated that the antidepressant effects of neuromodulation techniques are also associated with the modulation of certain brain functional circuits. Then, in this proposal, we will investigate both the whole brain and circuit specific functional MRI resting-state functional changes after right unilateral ECT in MDD patients, and its associations with clinical and cognitive dimensional subconstructs. At the end of the project, we aim to provide additional information regarding the functional neurobiological effects of ECT in MDD, that will be useful to compare with another convulsive therapy modality, the magnetic seizure therapy (MST), which is object of study in Brazil. (AU)