Does genetic risk for depression accelerate biological aging?

Major Depressive Disorder is a major contributor to aging-related health burdens. Preventing and managing depression symptoms are suggested strategies to reduce these burdens. However, the cooccurrence of depression and aging-related disease/disability could arise from reverse causation (i.e. aging-->depression) or confounding by a common cause (aging<- ->depression). We investigated the connection between depression and biological aging, a root cause of aging-related health decline, using US Health and Retirement Study (HRS) data and a genetic design to address potential confounding. We tested associations among polygenic scores measuring genetic risk for depression, longitudinal measurements of depression symptoms, and a measurement of biological aging in 3,806 White and 1,207 Black HRS participants. Results showed that participants with higher depression polygenic scores and more depression symptoms were biologically older than those of the same chronological age with lower genetic risk and fewer symptoms. However, depression symptoms mediated only a fraction of the association between genetic risk and biological aging. Findings suggest that the link between depression and aging burden may not be fully addressable through depression treatment in later life. Further research is needed to determine whether our findings reflect the accumulated effects of depressive symptoms earlier in life or some other pathway linking genetic risk for depression with accelerated biological aging.