Background. Antidepressant medications are commonly prescribed for pat
ients with chronic low back pain. A literature synthesis was performed
to determine whether antidepressants are more effective than placebos
in decreasing pain, disability, depression, and analgesic medication
use in such patients. Methods. English-language journal articles were
identified from MEDLINE and PsycLIT databases, bibliographies, and inq
uiries to researchers and drug companies. Articles were included if th
ey reported data from placebo-controlled or drug comparison trials of
antidepressants for patients with low back pain. Sh articles met these
criteria. Results. Three studies compared the effects of antidepressa
nts and placebos on pain; two found no difference and one found a tren
d toward superiority of imipramine for patient-rated symptoms but no d
ifference in investigator ratings. Effects on functional disability we
re examined in three antidepressant-placebo comparisons; only one foun
d the antidepressant to be more effective. Antidepressant effects of a
n antidepressant vs placebo were compared in three studies; none found
a significant difference. Effects on analgesic medication use were co
mpared in three studies; one found amitriptyline to be superior and th
e others found no difference. Serious methodologic flaws characterized
all six studies, and insufficient reporting of data precluded meta-an
alysis. Conclusions. The literature has not demonstrated that antidepr
essants are superior to placebos in improving low back pain or related
problems. However, further randomized controlled trials are needed to
determine whether antidepressants are useful for low back pain.