Effects of ECT on Memory Consolidation Process in Patients with Major Depressive Disorder

Abstract

Despite its longstanding successful use, the mechanisms of action of electroconvulsive therapy (ECT) are still not fully understood. Converging evidence shows that ECT is accompanied by widespread regional changes in gray matter volume and altered structural and functional connectivity. How these changes relate to ECT response remains to be further elucidated. It is highly conceivable that an interaction of imaging, genetic and biochemical factors related to neuronal plasticity contributes to the antidepressant effects of ECT. In this perspective, the aim of the present investigation is to detect predictive markers of ECT outcome in depressed patients by combining multimodal MRI with serum- and CSF-based laboratory measurements. Results of the study might be useful to establish an individualized medical indication for ECT.

In combination with the ongoing 3-years long study, we will try to develop a theoretical framework of how ECT affects the process of memory consolidation in patients with major depressive disorder. There is evidence that some patients report noticed memory impairments after obtaining ECT. With our theoretical framework, we want to claim against the latter statement. Because of onward depression before getting ECT; patients show to have reduced hippocampal volumes and recollection deficits in depression (stress-related inhibition), inhibited midbrain dopamine neurons and stress-related sensitization of the amygdala. All the listed structural and functional dysconnectivity highly affects the process of memory consolidation and causes memories not to be constructed. However, after successful ECT, structural and functional connectivity in the brain improves and memory can again consolidate naturally. Overall, ECT stabilizes the memory consolidation process of depressed patients, and that is in our regards, one of the main contributions to antidepressant effects of ECT for patients with major depressive disorder [1].

With our research we would like to bring more positive evidence in hands of obtaining ECT as a successful treatment for patients with major depressive disorder. Since ECT is still widely negatively accepted and can be taken as a taboo in modern society; it is very important to provide more papers on giving reasons for accepting ECT more positively and with less fear. In that way, ECT will also be able to be researched more and will because of that, improve the treatment itself. Hypothetically speaking, more researched ECT intervention could open windows for development of future treatments, for instance, treatment of neurodegenerative disorders (dementia).

References

[1] D. G. Dillon and D. A. Pizzagalli, “Mechanisms of memory disruption in depression,” Trends in Neurosciences, vol. 41, no. 3, pp. 137–149, Jan. 2018. doi:10.1016/j.tins.2017.12.006