WEST PALM BEACH, FLA. – Among patients with relapsing-remitting multiple sclerosis (MS), depression increases the likelihood of having worse neurologic function one year later, according to a study presented at ACTRIMS Forum 2020. Patients’ subjective descriptions of disease activity did not significantly change during that time, which “suggests that depression is not merely a reactive phenomenon, but rather an independent contributor to clinical worsening in the long term,” said Jenny Feng, MD, a neuroimmunology fellow at the Mellen Center for MS Treatment and Research at the Cleveland Clinic.
The researchers hypothesize that depression’s influence on psychomotor function may contribute to clinical worsening in MS.
More than half of patients with MS have depression, and there is a higher prevalence of depression in relapsing-remitting MS than in progressive disease. “Depression is associated with systemic inflammation,” Dr. Feng said at the meeting held by the Americas Committee for Treatment and Research in Multiple Sclerosis. “We know that depressed individuals tend to have slower walking speeds, slower processing speeds, and worse quality of life measures.” But neurologists do not know whether patients feel depressed because the disease is getting worse, or whether depression is an independent contributing factor to MS, Dr. Feng said.
To examine whether depression affects neurologic performance and disease activity in patients with MS, Dr. Feng and colleagues analyzed real-world data from about 2,400 patients in MS PATHS (Multiple Sclerosis Partners Advancing Technology and Health Solutions), a network of centers in the United States and Europe. The researchers assessed the longitudinal relationship between depression, measures of neurologic function, and MRI metrics.
The researchers included patients with relapsing-remitting MS who had clinical and imaging data available at baseline and about 1 year later. Patients completed tests of manual dexterity, walking speed, and processing speed that are based on the Multiple Sclerosis Functional Composite. A worsening of 20% on any measure is considered clinically significant.
Patients had a mean age of about 45 years and mean disease duration of about 14 years. Patients with a T score greater than 45 on the Neuro-QoL depression questionnaire were classified as having depression, and approximately half of the population had depression. Patients with depression were more likely to have an employment status of disabled and to receive infusion medications.
The investigators used propensity score analysis to adjust for baseline differences between patients with and without depression and evaluated the effect of depression on year 1 outcome measures using logistic regression for categorical variables and linear regression for continuous variables.
“After propensity weighting for baseline covariates including neuroperformance scores, individuals with depression continued to worsen,” Dr. Feng said. Patients with depression were more likely to have a 20% worsening in at least one measure of neurologic performance at year 1 (odds ratio, 1.31). “There was a trend for increased odds of interval relapses, increased T2 lesion burden, and contrast-enhancing lesions at year 1” in patients with depression, but the results were not statistically significant. “Despite worsening neuroperformance at year 1 in individuals with baseline depression, their [patient-reported outcomes] at year 1 were not significantly worse.”
The researcher lacked information about the date of depression onset and medication compliance, Dr. Feng said. In addition, propensity weighting does not account for potential bias due to missing data.
The findings support the existing practice of actively screening for and treating depression in patients with MS, Dr. Feng said.
Dr. Feng had no disclosures. Coauthors have consulted for and received research support from pharmaceutical companies. MS PATHS is supported by Biogen.
SOURCE: Feng JJ et al. ACTRIMS Forum 2020. Abstract P226.