Electroconvulsive therapy effects on anhedonia and reward circuitry anatomy: A dimensional structural neuroimaging approach

• Main Authors: Barbour, T. (Author), Camprodon, J.A (Author), Cano, M. (Author), Ellard, K. (Author), Lee, E. (Author), Soriano-Mas, C. (Author), Worthley, A. (Author)
• Format: Article
• Language: English
• Published: Elsevier B.V. 2022
• Subjects: Anhedonia; Anticipatory pleasure; Brain morphometry; Electroconvulsive therapy; Major depressive disorder; Reward system
• Online Access: View Fulltext in Publisher

 Background: Anhedonia is a core symptom of major depressive disorder (MDD) resulting from maladaptive reward processing. Electroconvulsive therapy (ECT) is an effective treatment for patients with MDD. No previous neuroimaging studies have taken a dimensional approach to assess whether ECT-induced volume changes are specifically related to improvements in anhedonia and positive valence emotional constructs. We aimed to assess the relationship between ECT-induced brain volumetric changes and improvement in anhedonia and reward processing in patients with MDD. Methods: We evaluated 15 patients with MDD before and after ECT. We used magnetic resonance imaging, clinical scales (i.e., Quick Inventory of Depressive Symptomatology for syndromal depression severity and Snaith-Hamilton Pleasure Scale for anhedonia) and the Temporal Experience of Pleasure Scale for anticipatory and consummatory experiences of pleasure. We identified 5 regions of interest within the reward circuit and a 6th control region relevant for MDD but not core to the reward system (Brodmann Area 25). Results: Anhedonia, anticipatory and consummatory reward processing improved after ECT. Volume increases within the right reward system separated anhedonia responders and non-responders. Improvement in anticipatory (but not consummatory) reward correlated with increases in volume in hippocampus, amygdala, ventral tegmental area and nucleus accumbens. Limitations: We evaluated a modest sample size of patients with concurrent pharmacological treatment using a subjective psychometric assessment. Conclusions: We highlight the importance of a dimensional and circuit-based approach to understanding target engagement and the mechanism of action of ECT, with the goal to define symptom- and circuit-specific response biomarkers for device neuromodulation therapies. © 2022