Electroconvulsive therapy induced large-scale grey matter increases do not lead to any significant functional brain changes

Abstract Electroconvulsive therapy (ECT) is an effective treatment for severe depression and induces gray matter increases in the brain. Small-scale studies suggest that ECT also leads to changes in brain functioning, but findings are inconsistent. In this talk, we will discuss our recent publication where we investigated the influence of ECT on changes in both brain structure and multiple measures of brain function and their relation to clinical improvement using multicenter neuroimaging data from the Global ECT-MRI Research Collaboration (GEMRIC). We found wide-spread increases in gray matter volume in patients following ECT. In contrast, no significant changes in any of the functional measures were observed, and there were no visible differences in structural or functional changes between ECT responders and non-responders. Multimodal analysis revealed that volume increases in the striatum, supplementary motor area and fusiform gyrus were associated with local changes in brain function. These results confirm wide-spread increases in GM volume, and suggest that this is not accompanied by functional changes or associated with clinical response. While focal changes in brain function appear related to individual differences in brain volume increases, we emphasize the need for approaches beyond standard activity measures of fMRI to investigate the working mechanism of ECT. Research Category and Technology and Methods Clinical Research: 2. Electroconvulsive Therapy (ECT) Keywords: Electroconvulsive Therapy, Gray matter, Brain Function, Neuroimaging