Exploring the Relationship Between Electroconvulsive Therapy and Reward Processing in Major Depressive Disorder

Depression affects over ten percent of the population worldwide, with a huge toll for patients, their families, and the whole society. Around one third of patients with depression does not respond satisfactorily or at all to either pharmacological or psychological therapy. Electro- convulsive therapy (ECT) is an established treatment for severe mental illnesses, in particular treatment-resistant depression, a leading contributor to global disease. Despite its proven effectiveness in treating depression, the underlying mechanisms of ECT are not yet fully understood. This thesis examines the potential differences between patients who respond positively to electroconvulsive therapy (ECT) and those who do not, providing novel insights into their relationship with the reward processing in the brain. While this thesis expands our knowledge of ECT effect in the treatment of depression, it is important to acknowledge that the study comes with at least two major limitations. (i) The small sample size may impact on the statistical power of the study; (ii) the computer task used to assess the reward processing may not be sensitive to detect subtle differences between groups or changes over time. It is possible that other measures will provide a more comprehensive assessment of reward functions in future evaluations. Future research with larger samples and more sensitive measures could build upon these findings and further advance our understanding of the mechanisms underlying ECT and treatment response in depression.