Depression is associated with decreased neurologic function and new brain lesions in patients with multiple sclerosis (MS), new research suggests.
In an observational study of more than 2500 patients with relapsing-remitting MS (RRMS), participants with self-reported depression were more likely to have worse scores on neuroperformance measures, such as processing speed tests, than their peers without depression.
At baseline, the group with depression also had greater odds of having at least one new contrast-enhancing lesion on MRI.
“Our results suggest that depression is not merely a reactive symptom but indicates increased risk of future MS disease activity,” the investigators note.
Lead author Jenny Feng, MD, clinical associate at the Mellen Center for MS Treatment and Research at Cleveland Clinic, added that depression should be routinely screened for in all patients with MS, something done routinely at her center.
“Every single patient that comes through the door with newly diagnosed MS, we refer to neuropsychology to screen for depression; and if there is depression, then we actively manage it because it does have an effect” on patients, she told Medscape Medical News.
“Depression isn’t just a neuropsychiatric disease,” Feng added. As shown in their study, “it may have effects on MS, especially with regards to performance in neurological function testing.”
The research is presented on AAN.com as part of the American Academy of Neurology 2020 Science Highlights. Because of the COVID-19 pandemic, the AAN had to cancel its 2020 annual meeting.
Associations Have Been “Unclear”
Although inflammatory, psychosocial, and neurodegenerative factors “have been hypothesized as etiologies” for why depression is commonly found in patients with MS,
For the current study, they assessed data from the Partners Advancing Technology and Health Solutions (MS-PATHS) database, an ongoing collaborative network of seven MS centers in the United States and three in Europe.
MS disease history and MRI data were examined, as well as 12-month scores on neuroperformance tests measuring processing speed (Symbol Digit Modalities Test), walking speed (Timed 25-Foot Walk), and manual dexterity (Nine-Hole Peg Test).
Patient-reported outcomes (PROs), as measured with the Quality of Life in Neurological Disorders (Neuro-QoL) and patient-determined disease steps, were also assessed. Depression was defined as a depression T score at baseline greater than “the 50th percentile” on the Neuro-QoL.
In the patient sample, 1333 of the participants with RRMS were classified as “not depressed” (73.7% women; mean age, 45.6 years; disease duration, 13.7 years) while 1172 were “depressed” (78.4% women; mean age, 45.9 years; disease duration, 14.3 years).
“To balance for baseline variances in the observational cohort between group with depression and group without depression, propensity score analysis was used to adjust for potential confounding factors,” the investigators report.
Worse Performance
After adjustment for baseline covariates, results showed that the depressed patients performed worse on the walking speed test (0.48; 95% confidence interval, 0.038-0.918) and processing speed test (–1.899; 95% CI, –3.548 to –0.250).
The depressed group also had increased odds at baseline of having new contrast-enhancing lesions (odds ratio, 5.89; 95% CI, 2.236-15.517). This demonstrated an “association of depression and neuroinflammatory activity” in the central nervous system, the investigators note.
At 12 months, processing speed continued to be worse in the depressed group (–1.68; 95% CI, –3.254 to –0.105).
There were trends, albeit insignificant, for decreased walking speed scores at 12 months and for decreased manual dexterity scores at both baseline and at 12 months for the participants who were depressed.
Interestingly, there were “no significant differences in PROs at month 12, despite worsening neuroperformance,” the investigators report.
“This means that patients themselves may not even realize that they were getting worse,” Feng said.