Patients with multiple sclerosis (MS) are reported to have major depressive disorder at twice the rates of the average population. Imaging studies of the brain indicate that disease activity may be be the cause for some cases. Although the exact mechanism remains unknown, depressed MS patients appear to have increased lesions in specific brain areas, including the right temporal lobe, left hemisphere suprasylvan region, and superior frontal or parietal regions. Drugs used to treat MS can also be associated with depression. Depressive symptoms may occur anytime during the course of MS, even in patients with very mild MS symptoms.
Reviews of death certificates indicated that suicide may be the cause of death in up to 15 percent of MS patients. Depression has been identified as the major risk factor for suicide. Social isolation, history of suicide attempts, and recent deterioration in function are also important factors. The level of neurological disability does not appear to be an independent factor.
For treatment, the first step is to determine whether medication used to treat MS is causing the depression. Corticosteroids and IFN-beta (Avonex, Rebif, and Betaseron) have been associated with neuropsychiatric side effects in some patients. Corticosteroids are reported to cause such effects in 5 to 8 percent of MS patients, including the following:
1. Depression
2. Mania
3. Euphoria
4. Hallucinations
5. Increased energy
6. Decreased sleep
7. Mood lability
Symptoms may be noted when corticosteroids are first used, or when they are discontinued, or with long-term use. It may be necessary to taper off gradually.
If the depression is not related to MS medication, treatment options include psychotherapy and standard antidepressants. However, there is not much data showing effectiveness of antidepressants in MS patients. Reference 1 reported a study comparing sertraline (Zoloft) to psychotherapy. In the sertraline group, 29 percent dropped out before completing the study, and only 24 percent had a response to treatment. Cognitive behavioral therapy had a much better response rate of 50 percent. A third group was assigned to supportive-expressive group therapy, and 14 percent responded favorably to this treatment. The authors reported that cognitive behavioral therapy delivered by telephone shows considerable promise.
A recent article in Scientific American explored the relationship between multiple sclerosis and depression. This is available free online (see References).
References:
1. Chwastiak LA et al, “Psychiatric issues in multiple sclerosis”, Psychiatr Clin North Am. 2007 Dec; 30(4): 803-17.
2. Scientific American article available online:
http://www.scientificamerican.com/podcast/episode.cfm?id=the-connection-between-multiple-scl-10-07-03
Linda Fugate is a scientist and writer in Austin, Texas. She has a Ph.D. in Physics and an M.S. in Macromolecular Science and Engineering. Her background includes academic and industrial research in materials science. She currently writes song lyrics and health articles.