Treatment of fibromyalgia with antidepressants: a meta-analysis

Fibromyalgia is a common, poorly understood musculoskeletal pain syndrome with limited therapeutic options.

To systematically review the efficacy of antidepressants in the treatment of fibromyalgia and examine whether this effect was independent of depression.

Meta-analysis of English-language, randomized, placebo-controlled trials. Studies were obtained from searching MEDLINE, EMBASE, and PSYCLIT (1966-1999), the Cochrane Library, unpublished literature, and bibliographies. We performed independent duplicate review of each study for both inclusion and data extraction.

Sixteen randomized, placebo-controlled trials were identified, of which 13 were appropriate for data extraction. There were 3 classes of antidepressants evaluated: tricyclics (9 trials), selective serotonin reuptake inhibitors (3 trials), and S-adenosylmethionine (2 trials). Overall, the quality of the studies was good (mean score 5.6, scale 0-8). The odds ratio for improvement with therapy was 4.2 (95% confidence interval [95% CI], 2.6 to 6.8). The pooled risk difference for these studies was 0.25 (95% CI, 0.16 to 0.34), which calculates to 4 (95% CI, 2.9 to 6.3) individuals needing treatment for 1 patient to experience symptom improvement. When the effect on individual symptoms was combined, antidepressants improved sleep, fatigue, pain, and well-being, but not trigger points. In the 5 studies where there was adequate assessment for an effect independent of depression, only 1 study found a correlation between symptom improvement and depression scores. Outcomes were not affected by class of agent or quality score using meta-regression.

Antidepressants are efficacious in treating many of the symptoms of fibromyalgia. Patients were more than 4 times as likely to report overall improvement, and reported moderate reductions in individual symptoms, particularly pain. Whether this effect is independent of depression needs further study.