Do antidepressant medications relieve chronic low back pain?

Journal of Family Practice, Dec, 1993 by Judith A. Turner, Mary C. Denny

Is there a significant difference between antidepressant medication and placebo in decreasing functional disability? Three studies examined this issue; only one found the antidepressant medication to be superior on any measure. Alcoff et al[31] found imipramine to be superior to placebo in increasing the frequency of certain recent daily activities, according to patients' self-report by questionnaire, but there were no significant differences between the antidepressant and the placebo in patient symptoms and physical findings as evaluated by the clinical investigators. Alcoff et al[31] speculate that both the patients and physicians may have correctly guessed whether the patient was receiving the active medication or the inert placebo because both groups were knowledgeable about side effects commonly associated with the medication. Goodkin et al[32] found the placebo to be superior to trazodone in decreasing disability as assessed by the Sickness Impact Profile[37] (an interviewer-administered form). Pheasant et al[34] found no difference between amitriptyline and an active placebo (atropine) in decreasing functional disability as rated by a physician or as measured by patient responses to an activity-restriction questionnaire.

Similarly, Jenkins et al[33] reported no clear benefit for imipramine over placebo in improving physical measures such as straight leg raise, and forward, backward, and lateral flexion obtained by a physician or physical therapist. However, no statistical analyses were presented. No assessment of change in overall daily functioning was included in this study.

Is there a significant difference between antidepressant medication and placebo in decreasing depression? Three studies[31-33] of patients with varying levels of depressive symptoms found no differences between placebos and antidepressants in effects on depression. However, each of these studies included some patients who were not depressed, and patients not depressed initially would not have much room to improve on depression measures. All three studies relied on the Beck Depression Inventory (BDI)[38] to measured change in depressive symptoms over the treatment trial. In the study by Alcoff et al,[31] only four patients were reported to be mildly depressed and three severely depressed initially, based on BDI scores. In the study by Goodkin et al,[32] initial mean BDI scores for the placebo and the drug treatment groups were moderate and comparable, and both groups had wide initial variability in depression levels. Jenkins et al[33] reported low and comparable baseline median scores for the drug and placebo groups and wide variability overall. In this study, a subsample of the 15 most depressed patients (8 given imipramine, 7 given placebo) appeared to experience greater abatement of their depressive symptoms from Emipramine than from the placebo, but this difference was not statistically significant. In the study by Ward et al[36] of patients who were all clinically depressed initially, doxepin and desipramine were associated with significant improvement in depression. The mean Hamilton Depression Rating Scale score for all patients decreased from 26.4 to 9.7 (P [less than] .001). A 40% or greater reduction in depressive symptoms was found in 73% of patients completing the study.