Patients diagnosed with the chronic pain disorder fibromyalgia are often depressed. We still don't know why. A 2003 study presented at the American College of Rheumatology Annual Scientific Meeting found no direct association between depression, extreme sensitivity to pain stimulus and how pain is processed in the brain in fibromyalgia. This was true whether or not the patients were diagnosed with clinical depression.
There is no consensus on how to treat fibromyalgia. Some physicians first treat the depression, thinking that is the primary problem and is causing the pain. This study suggests that pain and depression are actually separate processes - and that both probably need to be treated. Depressed fibromyalgia patients do not process pain differently than those who are not depressed.
Researchers applied pressure to the left thumbs of 30 fibromyalgia patients in order to produce slightly intense pain. Functional MRI scans were used to record brain activity, Researchers found no association between the level of depression and the intensity of activity in areas of the brain involved in pain processing. Researchers did find a link between the severity of depressive symptoms and brain activity in two areas of the brain not involved in pain intensity coding.
The researchers compared brain activity patterns of a seven fibromyalgia patients diagnosed with major depression to seven fibromyalgia patients without depression and to seven patients in a control group. They found no difference in the degree of pressure pain sensitivity and patterns of pain-elicited brain activity between fibromyalgia patients with depression and fibromyalgia patients without depression.
An American College of Rheumatology academic press release quoted lead author Thorsten Giesecke, MD as stating that “This study challenges the notion that psychiatric symptoms such as depression cause or influence the pain seen in fibromyalgia and other chronic pain conditions, and instead suggests that depression is a separate and somewhat independent process.”
Last updated 3/16/06
Source: Academic press release written by the American College of Rheumatology and posted to Newswise.
