Many people with the chronic pain disorder fibromyalgia have also suffered from depression, anxiety or other psychiatric conditions at some point in their lives - suggesting, researchers say, that the disorders have some common causes.

In a study of 336 adults with and without fibromyalgia, researchers found that those with the condition were substantially more likely to have ever had depression, bipolar disorder or an anxiety disorder. They also had higher rates of eating disorders and substance abuse problems.

In most cases, the psychiatric condition preceded the development of fibromyalgia, making it unlikely that the mood disturbances were simply a reaction to having chronic pain.

Fibromyalgia is a syndrome marked by widespread aches and pains, fatigue and sleep problems, among other symptoms; the cause is unknown, and there are no medications specifically approved for the condition. Treatment usually involves a combination of approaches, such as painkillers, antidepressants, behavioral therapy or exercise therapy.

The new findings, published in the Journal of Clinical Psychiatry, are based on a comparison of families with members affected by either fibromyalgia or rheumatoid arthritis, another condition marked by chronic pain.

Between both groups of families, there were 108 adults, nearly all women, with fibromyalgia and 228 without the condition.

Overall, those with fibromyalgia were almost three times more likely to have ever had major depression and nearly seven times more likely to have suffered an anxiety disorder. They also had a two to three times greater risk of eating disorders and substance abuse problems, and a much higher risk of bipolar disorder.

The associations between fibromyalgia and these psychiatric conditions suggest that there is some “shared vulnerability” at work, according to study chief Dr. Lesley M. Arnold, an associate professor of psychiatry at the University of Cincinnati College of Medicine.

“We are not saying that fibromyalgia is a psychiatric disorder,” Arnold told Reuters Health.

Rather, some people may be vulnerable to developing both fibromyalgia and certain psychiatric disorders - possibly because of genes, Arnold explained, or because of environmental factors such as chronic stress. But no one yet knows for certain.

Still, the evidence suggests that people with fibromyalgia should be screened for psychiatric disorders, according to Arnold. Even when people aren’t currently suffering any psychiatric symptoms, their mental health history can influence how their fibromyalgia is treated, she noted.

For example, Arnold explained, medication with both antidepressant and pain-relieving effects might be the first choice for people with a history of depression. Another option is cognitive behavioral therapy, which addresses harmful thought patterns and behaviors; this approach, Arnold said, might help fibromyalgia patients with a history of depression or anxiety disorders.

SOURCE: Journal of Clinical Psychiatry, August 2006.