Posted on November 12, 2001 at 12:40 p.m.
BIRMINGHAM, AL — Studies by researchers at the University of Alabama at Birmingham (UAB) reveal new findings about the association between emotion and pain. “Our studies show that emotion does influence pain perception; however, with some disorders, such as fibromyalgia, where the source of pain is unidentifiable, it is mistake to assume that the pain is solely psychological,” says Laurence A. Bradley, Ph.D., professor of medicine with the Division of Immunology and Rheumatology at UAB.
Lead investigators Leanne Cianfrini and Brian Kersh will present study findings during the American College of Rheumatology’s Annual Scientific Meeting, November 11-15, in San Francisco, California.
Cianfrini’s study examined brain responses to pain in patients with depression compared to those with fibromyalgia and those of healthy people. “The pain responses of patients with depression were similar to those of healthy people,” says Cianfrini. “However, pain responses of patients with fibromyalgia were much greater. This indicates that the pain associated with fibromyalgia is not solely the result of depression, often experienced by patients with this disorder.”
“With fibromyalgia, some physicians often cite psychological distress as the cause of pain,” says Bradley. “This study shows that depression is not the major cause of pain for these patients and may not even be a contributing factor.”
In a related study, Kersh and others found that patients with knee osteoarthritis experience greater emotional stress in response to pain than healthy people. “While both groups rated the intensity of pain the same, patients with knee osteoarthritis reported the pain significantly more unpleasant,” says Kersh.
Intensity and unpleasantness were measured based on descriptive words chosen from word groups. Words describing pain intensity ranged from flickering to wrenching. Words describing unpleasantness varied from annoying to unbearable. “Both groups chose similar words to describe intensity; however, chose different words to describe unpleasantness,” says Kersh. “Words selected by patients with knee osteoarthritis indicated they experienced much greater emotional response to pain,” says Kersh.
The difference identified in participants’ verbal assessment of pain correlated to the difference in brain activity observed between the two groups. “Patients with knee osteoarthritis showed greater brain activity in response to pain than healthy people,” says Kersh.
“With knee osteoarthritis the primary cause of pain is clearly identifiable,” says Bradley. “In this situation, there is a tendency to attribute the pain solely to the severity of the disease; however, this study shows that emotion is also involved.”
Overall, the studies have important implications for the diagnoses and treatment of chronic pain conditions. “In cases where the source of pain in clearly identifiable, it’s important to consider both the source of pain and the patient’s emotional stress as contributing factors,” says Bradley. “With disorders like fibromyalgia, where the source of pain is unknown, it is a mistake to attribute the pain solely to emotional stress.”