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.