Competing interests: None declared
Funding: MacArthur Foundation Initiative on Depression in Primary Care. This digest and commentary appeared in Evidence-Based Medicine, 2001; 6:77
Studies in any language were identified by searching MEDLINE (1966 to June 1999), PsycLIT (1974-1998), and EMBASE/Excerpta Medica (1974-1998) with the terms fibromyalgia, fibrositis, and fibromyositis combined with various terms for antidepressive agents (including specific drug names); the Cochrane Library Clinical Trials Registry and Database of Systematic Reviews; Federal Research in Progress to identify unpublished trials; and bibliographies of reviewed articles.
Studies were selected if they were randomized, placebo-controlled trials with at least 1 group receiving an antidepressant drug and if they reported measurable outcomes.
Data were extracted on setting; country; dose, duration, and follow-up of treatment; number of participants and demographics; assessment of comorbid disease; follow-up losses (i.e., unavailable for follow-up); adverse effects; and outcomes. Methodologic quality of individual trials was assessed using the Jadad scale.
We included 13 trials (mean sample size, 54; mean duration, 8.1 weeks) in the analysis. Mean quality score for the Jadad scale was 5.6 of a maximum of 8. Nine studies did not give the method of randomization, 7 had no intention-to-treat analysis, 3 inadequately assured blinding effectiveness, 5 did not assess adverse effects, and 6 had lower than 20% loss to follow-up. Trials assessed the efficacy of 3 classes of antidepressant drugs: tricyclic antidepressants (8 trials of amitriptyline hydrochloride, 1 of clomipramine hydrochloride, and 1 of maprotiline hydrochloride), S-adenosyl-1-methionine (2 trials), and selective serotonin reuptake inhibitors (2 of fluoxetine hydrochloride and 1 of citalopram hydrobromide).
Meta-analysis was done using a random-effects model. Meta-analysis of dichotomous outcome data (10 trials) showed that patients who received antidepressants had more symptom improvement than those who received placebo (odds ratio, 4.2 [95% confidence interval (CI), 2.6-6.8]; number needed to treat, 4 [95% CI, 2.9-6.3]). Meta-analysis of continuous outcome data showed that antidepressant drugs were associated with improvements in fatigue scores (8 trials, 0.39 SD unit improvement [95% CI, 0.11-0.66]), sleep scores (8 trials, 0.49 SD unit improvement [95% CI, 0.3-0.69]), pain scores (10 trials, 0.52 SD unit improvement [95% CI, 0.21-0.81]), and overall well-being (7 trials, 0.49 SD unit improvement [95% CI, 0.18-0.80]) but not in the number of trigger points.
Antidepressant drugs improve overall symptoms and individual symptoms of fatigue, sleep, and pain in patients with fibromyalgia.