Antidepressants to treat nonspecific low back pain

Background: Antidepressants are commonly used in the management of low back pain. However, their use is controversial. Objectives: The aim of this review was to determine whether antidepressants are more effective than placebo for the treatment of nonspecific low back pain. Search Strategy: Randomized controlled trials were identified from Medline and Embase (to September 2007), PsycINFO to June 2006, the Cochrane Central Register of Controlled Trials 2006, issue 2, and previous systematic reviews. Selection Criteria: The authors included randomized controlled trials that compared antidepressant medication with placebo for patients with nonspecific low back pain, and used at least one clinically relevant outcome measure. Data Collection and Analysis: Two blinded review authors independently extracted data and assessed the methodological quality of the trials. Meta-analyses were used to examine the effect of antidepressants on pain, depression, and function, and the effect of antidepressant type on pain. To account for studies that could not be pooled, additional qualitative analyses were performed using the levels of evidence recommended by the Cochrane Back Review Group. Main Results: Ten trials that compared antidepressants with placebo were included in this review. The pooled analyses showed no difference in pain relief (six trials; standardized mean difference [SMD] = -0.06; 95% confidence interval [CI], -0.28 to 0.16) or depression (two trials; SMD = 0.06; 95% CI, -0.29 to 0.40) between antidepressant and placebo treatments. The qualitative analyses found conflicting evidence on the effect of antidepressants on pain intensity in chronic low back pain, and no clear evidence that antidepressants reduce depression in patients with chronic low back pain. Two pooled analyses showed no difference in pain relief between different types of antidepressants and placebo. The authors' findings were not altered by the sensitivity analyses, which varied the level of methodological quality required for inclusion in the meta-analyses to allow data from additional trials to be examined. Two additional trials were identified in September 2007 and await assessment. Authors' Conclusions: There is no clear evidence that antidepressants are more effective than placebo in the management of patients with chronic low back pain. These findings do not imply that severely depressed patients with back pain should not be treated with antidepressants; furthermore, there is evidence for their use in other forms of chronic pain.