According to the University of California, alterations in hippocampal structural connections differentiate responders of electroshock therapy in depression.
A new study in people with major depression reports that electroshock therapy (also known as electroconvulsive therapy/ECT) induces changes in the fibres connecting the hippocampus to brain regions involved in mood and emotion. Only patients who responded to the treatment showed these changes, and those who had the greatest changes in hippocampal pathways also showed the largest improvements in mood. The study, conducted by researchers at University of California, USA, was published in Biological Psychiatry: Cognitive Neuroscience and Neuroimaging.
Believe it or not electroshock therapy is still a thing
ECT (Electroconvulsive Therapy) is a treatment that involves sending an electric current through the brain to trigger an epileptic seizure to relieve the symptoms of some mental health problem.
The treatment is given under a general anaesthetic and using muscle relaxants, so that muscles only twitch slightly, and the body does not convulse during the seizure.
The findings reveal that electroshock therapy causes subtle changes in the structural integrity of the fibre paths, which can affect how well information is transferred between brain regions.
Katherine Narr, PhD and senior author, explains: “The nature of these changes suggests plasticity in the brain’s structural connections contribute to successful therapeutic response.”
“ECT is highly effective for treating patients with severe depression who have not benefited from standard antidepressant treatments. However, researchers are still trying to understand how and why ECT works to improve depressive symptoms.”
Conducting brain scans on the hippocampal structural connections
The researchers conducted brain scans of the hippocampus, the brain region most affected by depression, in people with the disorder before and after electroshock therapy, and assessed the changes in mood of participants.
Because the changes in structural integrity of the hippocampal pathways were only observed in patients who responded to electroshock therapy, the findings suggest that it produces its therapeutic effects in the brain by improving this structural integrity.
“These data add to the growing evidence that response to ECT is associated with changes in brain structure, in this case anatomical measures of white matter, in individuals undergoing this treatment for major depression,” adds Cameron Carter, MD, Editor of Biological Psychiatry: Cognitive Neuroscience and Neuroimaging.
Hippocampal structural connectivity before electroconvulsive therapy was not related to treatment response, which means that the measures cannot be used to predict how a patient will respond to electroshock therapy.
Despite that, the connection between the structural changes induced by electroshock therapy and therapeutic response suggests that changes of hippocampal structural connectivity could be used during the development of new treatments to test how effective they are.