Study Finds Depression May Increase Mortality Risks in Patients With MS

Patients with multiple sclerosis (MS) may face a higher risk of death over the next decade if they also have depression, according to an article published in Neurology.

The study, conducted by the American Academy of Neurology, also found that patients with MS and depression may have an increased risk of developing vascular diseases, such as heart attack and stroke, compared with patients who just have MS.

“These findings underscore the importance of identifying depression in people with MS as well as monitoring for other risk factors for heart disease and stroke,” said Raffaele Palladino, MD, PhD, a study author and faculty member at Imperial College of London, in a statement.

The investigators enrolled 12,251 patients with MS and 72,572 people who did not have MS. They analyzed medical records to see whether vascular disease or death occurred over a period of 10 years. Among the patients with MS, 21% had depression at the beginning of the study, while 9% of the people without MS did as well.

The results show that people with both MS and depression had an overall mortality rate of 10.3 cases per 100,000 person-years, which accounts for the number of people in the study and the amount of time spent in the study. The mortality rate was 10.6 for patients with MS but not depression, 3.6 for people who had depression but not MS, and 2.5 for people with neither condition.

After adjusting for confounding factors, such as smoking status and diabetes, the investigators found that people with MS and depressions were more than 5 times more likely to die during the next decade than people who did not have either condition. Additionally, people with MS without depression were almost 4 times more likely to die than people with neither condition. People with depression but not MS were almost 2 times as likely to die than people without depression and/or MS.

The risk of developing vascular disease was 2.4 cases per 100,000 person-years for people with both MS and depression, and this dipped to 1.3 for people with depression but not MS, 1.2 for people with MS without depression, and 0.7 for people without MS and depression.

When adjusting for confounding factors, the investigators found that people with both conditions were over 3 times as likely to develop vascular disease compared with people without either condition.

“When we looked at the risk of death, we found that the joint effect of MS plus depression equaled more than the effect for each individual factor alone—in other words, the 2 conditions had a synergistic effect…. A total of 14% of the effect on mortality rate could be attributed to the interaction between these 2 conditions,” Palladino said.

A main limitation of the study was the lack of information on risk factors, including body mass index, which could impact the risks of developing vascular disease and mortality.

“Future studies need to be conducted to look at whether treating depression in people with MS could reduce the risk of vascular disease as well as death over time,” noted Palladino.

Reference

Having MS plus depression may be tied to increased risk of death. Press release. American Academy of Neurology. September 1, 2021. Accessed August 31, 2021. https://www.eurekalert.org/news-releases/926566?