Depression worsens vascular, mortality outcomes in MS

Depression appeared to increase risk for incident vascular disease and mortality among individuals with MS, according to results of a population-based retrospective matched cohort study published in Neurology.

“In the general population, depression is associated with a 30% increased relative risk of developing vascular disease and a 70% increased relative risk of all-cause mortality,” Raffaele Palladino, MD, PhD, of the department of primary care and public health at Imperial College of London in the U.K., and colleagues wrote. “Moreover, the more severe the depression, the higher the risk of onset of vascular disease and associated mortality. However, much less is known about these associations in the MS population.”

Palladino and colleagues aimed to evaluate whether the links between depression, vascular disease and mortality differed among people with MS (n = 12,251) and a control cohort without MS (n = 72,572). Investigators matched participants according to age, sex and general practice site in England, then stratified patients by depression status. Patients in the MS cohort received diagnosis between Jan. 1, 1987, and Sept. 30, 2018. To evaluate the relationship between MS, depression and time to incident vascular disease and mortality, researchers used time-varying Cox proportional hazard regression models. They also stratified analyses by sex.

Results showed depression in 21% in the MS cohort and 9% in the control cohort. Those with MS had increased risk for incident vascular disease regardless of the presence of comorbid depression compared with matched control participants without depression. Palladino and colleagues noted 10-year risk for all-cause mortality was 1.75 times greater among controls with depression (95% CI, 1.59-1.91), 3.88 times greater among individuals with MS without depression (95% CI, 3.66-4.1) and 5.43 times greater among individuals with MS and depression (95% CI, 4.88-5.96). Further, they reported a synergistic interaction between MS and depression, with the interaction dictating 14% of the observed effect. They confirmed differences in hazard ratios via sex-stratified analyses.

“These findings build on our previous work which showed an overall 30% increased hazard of any macrovascular disease compared to a matched control population and underscore the importance of identifying depression in the MS population,” Palladino and colleagues wrote. “Additional studies should be conducted to evaluate whether effectively treating depression in the MS population (perhaps with a lower threshold than those not affected by MS) reduces the risk of incident vascular disease and therefore reduces disability progression and mortality.”