Wednesday, June 06, 2007
Jacquelyn K. Beals
June 6, 2007 (Washington, DC) — A study of multiple sclerosis (MS) patients diagnosed with major depressive disorder (MDD) and/or dysthymia shows no relation between antidepressant use and improved outcomes.
A poster presentation here at the 21st annual meeting of the Consortium of Multiple Sclerosis Centers reported the results of a University of Washington study involving 96 MS patients enrolled in a trial investigating the value of exercise as a treatment for depression. Inclusion criteria for the study were a diagnosis of MDD and/or dysthymia based on the Structured Clinical Interview for the Diagnostic and Statistical Manual of Mental Disorders, 4th ed (DSM-IV).
Investigators became aware that some subjects in the primary study were being treated with antidepressants and some were not. This offshoot study investigated the proportion of people with MS and MDD and/or dysthymia taking antidepressants and assessed behavioral variables associated with antidepressant use.
Celeste Hunter, from the Multiple Sclerosis Rehabilitation Research and Training Center, University of Washington, in Seattle, and an author of the poster, explained to Medscape that 1 of her colleagues noticed that although all patients in the study suffered from clinical depression, there appeared to be no discernible difference in terms of affect between patients who took antidepressants and those who did not.
"Depression is harder to pin down in patients with MS," Ms. Hunter said. "I see the MS patients as being more emotionally reactive in a given situation than if they didn't have MS. The unpredictability factor is so important — they don't know, if they have a really bad exacerbation, whether they'll get the same function back as before."
Almost half of the patients in this group (44%) were not taking antidepressants. Those on treatment were receiving various agents.
Patient-Reported Antidepressant Use
Subjects were 85% female, 42.7% employed, and 91.7% white. Their Expanded Disability Status Scale scores were 4 or less in 52.1%, 4.5 to 6.0 in 45.8%, and 6.5 or more in 2.1%.
The researchers compared patients taking antidepressants (n = 54) with those not taking antidepressants (n = 42) — using the Hamilton Rating Scale for Depression, the Hopkins Symptom Checklist, the Modified Fatigue Impact Scale, item 8 of the Brief Pain Inventory, and the Expanded Disability Status Scale — and found no significant difference between the outcome scores of the 2 groups on any of these scales.
The authors concluded, "Because the study did not include people who were on antidepressants and not suffering from current MDD, our results may have been biased against finding improved outcomes associated with antidepressant use." Further studies in this area of MS treatment are needed, they added.
Kurt Johnson, PhD, a professor in the department of rehabilitation medicine at the University of Washington, but not an author of this study, commented to Medscape that there has not been much evidence in the MS literature that antidepressants are useful in treating depression. "We found the same thing in another study with a larger group of people. A lot of people in our sample were taking antidepressants when they weren't depressed, and a lot were depressed but were not taking antidepressants."
Higher Incidence of Depression
Medscape also talked with Stephen Kirzinger, MD, from the Multiple Sclerosis Care Center Program, Department of Neurology, University of Louisville, in Kentucky, about this poster. "Certainly we feel that patients who have a chronic disease can develop a reactive depression, but in the MS population the incidence is much greater than what you would expect, comparing it with other chronic-disease processes," said Dr. Kirzinger. "So we feel it is a manifestation of the disease that our patients, because of their MS activity, actually have a chemical change that leads to depression."
The antidepressants listed by patients participating in this study are serotonin reuptake inhibitors. Dr. Kirzinger noted that some preliminary data have indicated that serotonin itself has a beneficial effect on the immune system. "I think the present study flies in the face of most of our clinical experience [in which] the patients who have depression seem to respond to antidepressants. The fact that they did not see a dramatic difference between those on antidepressants and those not taking antidepressants is a little surprising."
This study was funded by the National Rehabilitation Research and Training Center on Multiple Sclerosis from the US Department of Education, National Institute on Disability and Rehabilitation Research.
Consortium of Multiple Sclerosis Centers 21st annual meeting: Abstract S110. Presented June 1, 2007.
Mood Symptoms of Depression Vary Over Time in Multiple Sclerosis Patients
Depression Resource Center
Multiple Sclerosis (MS)