Treatment of fibromyalgia with antidepressants: a meta-analysis

Abstract

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

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

Design: 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 Studies were obtained from searching MEDLINE, EMBASE, and PSYCLIT (1966-1999), the Cochrane Library, unpublished literature, and bibliographies.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.

Main results: 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.

Conclusion: 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.

FIGURE 1

Individual study and summary effect size on the dichotomous outcome of “improvement.” OR indicates odds ratio; CI, confidence interval.

FIGURE 2

Individual study and summary effect size on multiple continuous outcomes: pain, well-being, sleep, fatigue, and trigger points. CI indicates confidence interval.