Relationship Between Interpersonal Deressive Symptoms and Reduced Amygdala Volume in People with Multiple Sclerosis: Considerations for Clinical Practice

Background: The lifetime prevalence of depression in people with multiple sclerosis (MS) is approximately 50% compared with around 16% in the general population. There is a relationship between depression and quality of life in people with MS and evidence that depression may contribute to disease progression. Methods: This cross-sectional pilot study assessed the association between depression and regional brain atrophy, including amygdala and hippocampal volume. Forty-nine participants with MS recruited through a hospital MS clinic were administered the Center for Epidemiological Studies Depression Scale Revised (CESD-R) to investigate whether higher endorsement on the items depressive affect and interpersonal symptoms were associated with volumetric magnetic resonance imaging measurements of hippocampal and amygdala atrophy. Results: Regression analysis revealed an association between depression-related interpersonal symptoms and right amygdala volume. No association was found between depression and hippocampal volume. Conclusions: These results provide preliminary support for a unilateral, biologically based relationship between the right amygdala and characteristic interpersonal depressive symptoms expressed by people with MS and add to the growing body of literature implicating regional brain atrophy in MS-associated depression. Given that the interpersonal subcomponent of the CESD-R measures social functioning, and the neural networks in the amygdala are known to be implicated in processing social stimuli, this research suggests that targeted diagnosis and treatments for depression in people with MS may be particularly beneficial in this population. Further confirmatory research of this relationship is required.