Depression and the chronic pain syndrome fibromyalgia are common in patients who suffer from chronic Lyme disease and seem to correlate with poor functional outcomes, results of a study indicate.

The term chronic Lyme disease describes patients with persistent Lyme disease despite prior treatment with a conventional 2- to 4-week course of antibiotics.

Dr. Afton L. Hassett from the University of Medicine and Dentistry of New Jersey-Robert Wood Johnson Medical School, New Brunswick and colleagues studied 159 patients seen at an academic Lyme disease referral center.

They evaluated the prevalence and role of psychiatric “co-morbid” illness and psychological factors in 77 patients with chronic Lyme disease and 82 (comparison) patients without chronic Lyme disease. The comparison patients either recovered from Lyme disease or had Lyme-like symptoms explained by other conditions.

The investigators found that depression and anxiety disorders were far more prevalent in chronic Lyme disease patients than in comparison patients.

The chronic Lyme disease patients were also more apt to report pain and had higher levels of negative feelings and lower levels of positive feelings. They also had a greater number of symptoms and worse functioning.

The results, related to the prevalence of depression and anxiety and the powerful role of psychological variables in functional outcomes, were “striking and more pronounced than we expected,” Hassett noted in comments to Reuters Health.

“This is not to say that patients’ symptoms are purely psychological because in most cases they are not, but it is clear that depression and anxiety are common in this and many medical populations and need to be treated,” he added.

The study also showed that almost 47 percent of the chronic Lyme disease patients qualified for a diagnosis of fibromyalgia. “Sleep disturbance is common in most patients with fibromyalgia and this appeared to be the case in many of our chronic Lyme disease subjects,” Hassett mentioned. “Often detecting and treating the sleep problems can result in significant symptomatic improvement,” he added.

SOURCE: Arthritis and Rheumatism, December 2008.