Antidepressants in chronic pain: a review of efficacy.

Antidepressant drugs have gained widespread clinical usage alone or as adjuncts in the treatment of chronic pain disorders. Of 17 controlled studies of antidepressants in chronic pain, 13 demonstrated significant pain relief with antidepressants compared to placebo. These studies were too different from one another to allow any general conclusions concerning efficacy, however. Five studies of either migraine or chronic tension headache all demonstrated superior efficacy of antidepressants versus placebo, while those of back and arthritic pain yielded mixed results. Of 3 studies of pain of several etiologies, 2 failed to demonstrate efficacy of antidepressants over placebo. These studies do not provide answers to many clinical questions on the use of antidepressants for chronic pain, such as drug of choice or appropriate dosage. Rather, they suggest that these agents may be beneficial in some patients with chronic pain.