Researchers at the University of Michigan Health System and the University of Cologne, Germany, have used functional imaging of the brain to determine that in patients with the chronic pain syndrome fibromyalgia, their level of depression has little influence on the intensity of pain they experience. This could be one of the reasons that treating a patient's depression by prescribing an antidepressant that has no analgesic (pain-killing) properties may have little or no impact on their pain.
The study, in the May issue of Arthritis & Rheumatism, notes that doctors often lump together the two conditions when they treat patients experiencing both of them. Some 30 to 54 percent of people with chronic pain also have a major depressive disorder.
"There is an incorrect impression among many doctors that if you treat a patient's depression, it will make their pain better. Not so," says Daniel J. Clauw, M.D., one of the authors of the paper. Clauw is director of the U-M Chronic Pain and Fatigue Research Center and professor of rheumatology at the U-M Medical School. "If someone has pain and depression, you have to treat both."
The study involved 33 women and 20 men with fibromyalgia, a type of chronic pain that affects several million people, more often in women than in men, and typically involves tenderness to the touch, stiffness and fatigue. In addition to those 53 patients, another 42 healthy companion participants were involved in the study.
The testing included a measurement of pain experienced by subjects based on their tolerance of pressure applied to their left thumbnails using a hard rubber probe. Researchers a
Contact: Katie Gazella
University of Michigan Health System