SEATTLE – , according to an interim analysis described at the annual meeting of the Consortium of Multiple Sclerosis Centers.
Depression, a common psychiatric comorbidity in MS, is associated with excess morbidity and mortality in that population. Treatment with disease-modifying therapy (DMT) could influence the cause and symptoms of depression.
Youkyung S. Roh, a medical student at Johns Hopkins University in Baltimore, and colleagues hypothesized that lower-efficacy DMTs may increase the risk of depression, whereas higher-efficacy DMTs may have antidepressive properties, possibly because of their anti-inflammatory effects.
To test this hypothesis, Ms. Roh and her colleagues examined data from MS Partners Advancing Technology and Health Solutions (MS PATHS), an ongoing, 10-site, longitudinal study. They compared the rates of change in depressive symptom severity, as measured by the(Neuro-QoL) depression subscale, between patients initiating a lower-efficacy DMT and those initiating a higher-efficacy DMT. Eligible participants had relapsing-remitting MS, were new initiators of DMTs, and completed baseline and follow-up Neuro-QoL depression scales. The researchers defined lower-efficacy DMTs as interferons, , , and . Higher-efficacy DMTs were defined as , , , and .
The investigators used multivariable-adjusted, mixed-effects regression models to compare the rates of change in Neuro-QoL depression scores for patients with MS who were initiating higher-efficacy DMTs versus those initiating lower-efficacy DMTs. Secondary analyses excluded interferons from the lower-efficacy DMT category.
In addition, the investigators compared the rates of depression between therapies within each class of DMT efficacy. Other analyses were stratified by sex, race, disability status, and antidepressant use.
The investigators’ interim analyses included 1,501 participants who initiated a new therapy and who had baseline and follow-up Neuro-QoL depression scores. The mean age of the study population was 45.1 years, and 76% of participants were women. Average follow-up duration was just under 1 year.
In all, 922 participants initiated lower-efficacy DMTs, and 579 participants initiated higher-efficacy DMTs. In preliminary analyses, initiation of higher-efficacy DMT was associated with a multivariable-adjusted 0.58-points/year reduction in Neuro-QoL depression scores, compared with initiation of lower-efficacy DMT. The result was statistically significant.
In addition, results were consistent in analyses that excluded interferons from the category of lower-efficacy DMTs. In those analyses, the reduction in depression scores was 0.63 points/year, which was also statistically significant.
Analyses incorporating additional follow-up data from this cohort are ongoing, said the authors.
The study was not supported by outside funding. Ellen M. Mowry, MD, one of the investigators, reported having performed contracted research for Biogen, Genzyme, and Sun Pharma. Ms Youkyung and another two investigators reported no disclosures or conflicts of interest.