BACKGROUND: Randomized trials with antidepressants are often run under double blind placebo-controlled conditions, whereas those with psychotherapies are mostly unblinded. This can introduce bias in favor of psychotherapy when the treatments are directly compared. In this meta-analysis, we examine this potential source of bias. METHODS: We searched Pubmed, PsycInfo, Embase and the Cochrane database (1966 to January  2014) by combining terms indicative of psychological treatment and @entity308 , and limited to randomized trials. We included 35  trials (with 3721  @entity1 ) in which psychotherapy and pharmacotherapy for adult @entity308 were directly compared with each other. We calculated effect sizes for each study indicating the difference between psychotherapy and pharmacotherapy at post-test. Then, we examined the difference between studies with a placebo condition and those without in moderator analyses. RESULTS: We did not find a significant difference between the studies with and those without a placebo condition. The studies in which a placebo condition was included indicated no significant difference between psychotherapy and pharmacotherapy (g=-0.07; NNT=25). Studies in which no placebo condition was included (and @entity1 and clinicians in both conditions were not blinded), resulted in a small, but significant difference between psychotherapy and pharmacotherapy in favor of pharmacotherapy (g=-0.13; NNT=14). CONCLUSIONS: Studies comparing psychotherapy and pharmacotherapy in which both groups of @entity1 (and therapists) are not blinded (no placebo condition is included) result in a very small, but significantly higher effect for pharmacotherapy.

The effects of blinding on the outcomes of psychotherapy and pharmacotherapy for adult XXXX : A meta-analysis.

@entity1 :: ('9606', 'Species') :: ['patients'] @entity308 :: ('MESH:D003866', 'Disease') :: ['depression']
@entity308 :: (MESH:D003866,Disease) :: ['depression']
