title: Comparison of psychotherapies for adult depression to pill placebo control groups: a meta-analysis.
abstract: BACKGROUND
  The effects of antidepressants for treating depressive disorders have been overestimated because of selective publication of positive trials. Reanalyses that include unpublished trials have yielded reduced effect sizes. This in turn has led to claims that antidepressants have clinically insignificant advantages over placebo and that psychotherapy is therefore a better alternative. To test this, we conducted a meta-analysis of studies comparing psychotherapy with pill placebo.
  
  
  METHODS
  Ten 10 studies comparing psychotherapies with pill placebo were identified. In total, 1240 patients were included in these studies. For each study, Hedges' g was calculated. Characteristics of the studies were extracted for subgroup and meta-regression analyses.
  
  
  RESULTS
  The effect of psychotherapy compared to pill placebo at post-test was g = 0.25 [95% confidence interval (CI) 0.14-0.36, I² = 0%, 95% CI 0-58]. This effect size corresponds to a number needed to treat (NNT) of 7.14 (95% CI 5.00-12.82). The psychotherapy conditions scored 2.66 points lower on the Hamilton Depression Rating Scale (HAMD) than the placebo conditions, and 3.20 points lower on the Beck Depression Inventory (BDI). Some indications for publication bias were found (two missing studies). We found no significant differences between subgroups of the studies and in meta-regression analyses we found no significant association between baseline severity and effect size.
  
  
  CONCLUSIONS
  Although there are differences between the role of placebo in psychotherapy and pharmacotherapy research, psychotherapy has an effect size that is comparable to that of antidepressant medications. Whether these effects should be deemed clinically relevant remains open to debate.
authors.affiliation: Department of Clinical Psychology, VU University Amsterdam, The Netherlands.
authors.forename: P
authors.initials: P
authors.lastname: Cuijpers
authors.affiliation: Behavioral Health and Neurosciences Division, Portland Veterans Affairs Medical Center, Portland, OR, USA.
authors.forename: E H
authors.initials: EH
authors.lastname: Turner
authors.affiliation: Department of Preventive Medicine, Northwestern University, Chicago, IL, USA.
authors.forename: D C
authors.initials: DC
authors.lastname: Mohr
authors.affiliation: Department of Psychology, Boston University, Boston, MA, USA.
authors.forename: S G
authors.initials: SG
authors.lastname: Hofmann
authors.affiliation: Department of Behavioral Sciences and Learning, Swedish Institute for Disability Research, Linköping University, Sweden.
authors.forename: G
authors.initials: G
authors.lastname: Andersson
authors.affiliation: Department of Clinical Psychology, Philipps-University of Marburg, Germany.
authors.forename: M
authors.initials: M
authors.lastname: Berking
authors.affiliation: Health Psychology Section, Department of Health Sciences, University Medical Center, Groningen, University of Groningen, The Netherlands.
authors.forename: J
authors.initials: J
authors.lastname: Coyne
mesh_terms: D000328:Adult; D003866:Depressive Disorder / Q000628:therapy*; D006801:Humans; D010919:Placebos / Q000494:pharmacology*; D011613:Psychotherapy / Q000379:methods*
chemical_list: D010919:Placebos