Da. Fishbain et al., DO ANTIDEPRESSANTS HAVE AN ANALGESIC EFFECT IN PSYCHOGENIC PAIN AND SOMATOFORM PAIN DISORDER - A METAANALYSIS, Psychosomatic medicine, 60(4), 1998, pp. 503-509
Objective: A significant amount of evidence indicates that some antide
pressants have an analgesic effect. We wished to determine whether thi
s analgesic effect could be demonstrated in studies that had used anti
depressants for the treatment of pain in patients diagnosed with psych
ogenic pain or somatoform pain disorder. Meta-analysis was used for th
is purpose. Methods: All randomized, placebo-controlled antidepressant
treatment studies of patients diagnosed with psychogenic pain disorde
r or somatoform pain disorder were isolated. These studies were review
ed and relevant statistics were coded. For each study, a single p valu
e for the drug/placebo comparison was found or calculated for pain cha
nge scores from pretreatment to completion of treatment. The z scores
and effect sizes were calculated for each study, followed by a calcula
tion of an overall z score and effect size. Results: Eleven studies fu
lfilled the inclusion and exclusion criteria for this meta-analysis. T
he combined difference showed that antidepressants decreased pain inte
nsity in patients with psychogenic pain or somatoform pain disorder si
gnificantly more than placebo (z = 5.71, p <.0001). The overall effect
size was large (mean = 0.48) and ranged from 0 to 0.91. Conclusions:
The results indicate that, in patients diagnosed with psychogenic pain
or somatoform pain disorder, antidepressant treatment resulted in a r
eduction in pain that was significantly greater than that of placebo.
Possible explanations for these results are discussed.