TY - JOUR
T1 - Electroconvulsive therapy disrupts functional connectivity between hippocampus and posterior default mode network
AU - Gbyl, Krzysztof
AU - Labanauskas, Vytautas
AU - Lundsgaard, Christoffer Cramer
AU - Mathiassen, André
AU - Ryszczuk, Adam
AU - Siebner, Hartwig Roman
AU - Rostrup, Egill
AU - Madsen, Kristoffer
AU - Videbech, Poul
N1 - Publisher Copyright:
© 2024 The Authors
PY - 2024
Y1 - 2024
N2 - Background: The mechanisms underlying memory deficits after electroconvulsive therapy (ECT) remain unclear but altered functional interactions between hippocampus and neocortex may play a role. Objectives: To test whether ECT reduces functional connectivity between hippocampus and posterior regions of the default mode network (DMN) and to examine whether altered hippocampal-neocortical functional connectivity correlates with memory impairment. A secondary aim was to explore if these connectivity changes are present 6 months after ECT. Methods: In-patients with severe depression (n = 35) received bitemporal ECT. Functional connectivity of the hippocampus was probed with resting-state fMRI before the first ECT-session, after the end of ECT, and at a six-month follow-up. Memory was assessed with the Verbal Learning Test – Delayed Recall. Seed-based connectivity analyses established connectivity of four hippocampal seeds, covering the anterior and posterior parts of the right and left hippocampus. Results: Compared to baseline, three of four hippocampal seeds became less connected to the core nodes of the posterior DMN in the week after ECT with Cohen's d ranging from −0.9 to −1.1. At the group level, patients showed post-ECT memory impairment, but individual changes in delayed recall were not correlated with the reduction in hippocampus-DMN connectivity. At six-month follow-up, no significant hippocampus-DMN reductions in connectivity were evident relative to pre-ECT, and memory scores had returned to baseline. Conclusion: ECT leads to a temporary disruption of functional hippocampus-DMN connectivity in patients with severe depression, but the change in connectivity strength is not related to the individual memory impairment.
AB - Background: The mechanisms underlying memory deficits after electroconvulsive therapy (ECT) remain unclear but altered functional interactions between hippocampus and neocortex may play a role. Objectives: To test whether ECT reduces functional connectivity between hippocampus and posterior regions of the default mode network (DMN) and to examine whether altered hippocampal-neocortical functional connectivity correlates with memory impairment. A secondary aim was to explore if these connectivity changes are present 6 months after ECT. Methods: In-patients with severe depression (n = 35) received bitemporal ECT. Functional connectivity of the hippocampus was probed with resting-state fMRI before the first ECT-session, after the end of ECT, and at a six-month follow-up. Memory was assessed with the Verbal Learning Test – Delayed Recall. Seed-based connectivity analyses established connectivity of four hippocampal seeds, covering the anterior and posterior parts of the right and left hippocampus. Results: Compared to baseline, three of four hippocampal seeds became less connected to the core nodes of the posterior DMN in the week after ECT with Cohen's d ranging from −0.9 to −1.1. At the group level, patients showed post-ECT memory impairment, but individual changes in delayed recall were not correlated with the reduction in hippocampus-DMN connectivity. At six-month follow-up, no significant hippocampus-DMN reductions in connectivity were evident relative to pre-ECT, and memory scores had returned to baseline. Conclusion: ECT leads to a temporary disruption of functional hippocampus-DMN connectivity in patients with severe depression, but the change in connectivity strength is not related to the individual memory impairment.
KW - Electroconvulsive therapy
KW - Hippocampus
KW - Major depressive disorder
KW - Resting state fMRI
U2 - 10.1016/j.pnpbp.2024.110981
DO - 10.1016/j.pnpbp.2024.110981
M3 - Journal article
C2 - 38373628
AN - SCOPUS:85186585657
VL - 132
JO - Progress in Neuro-Psychopharmacology & Biological Psychiatry
JF - Progress in Neuro-Psychopharmacology & Biological Psychiatry
SN - 0278-5846
M1 - 110981
ER -