title: Group cognitive behavioural therapy for obsessive-compulsive disorder: a systematic review and meta-analysis.
abstract: OBJECTIVE
  Behaviour therapy with exposure and response prevention (ERP) or cognitive behavioural therapy (CBT) including ERP are considered the psychological treatments of choice for obsessive-compulsive disorder (OCD), but group CBT/ERP has received relatively little research attention in the treatment of OCD. The aim of this study was to provide a meta-analysis of the effectiveness of group CBT/ERP for OCD.
  
  
  METHODS
  A systematic literature search was conducted and studies were meta-analysed by means of the Cochrane Review Manager Program with measures of i) pre- to post-effect sizes (ES) and ii) between-group ES in comparison with different control conditions. Outcome was primarily measured on the Y-BOCS and ES was calculated in the form of Cohens d.
  
  
  RESULTS
  Thirteen trials were included in the meta-analysis. The overall pre-post-ES of these trials of 1.18 and a between-group ES of 1.12 compared with waiting list control in three randomized controlled studies indicate that group CBT/ERP is an effective treatment for OCD. Group CBT achieved better results than pharmacological treatment in two studies. One study found no significant differences between individual and group CBT.
  
  
  CONCLUSIONS
  Group CBT is an effective treatment for OCD, but more studies are needed to compare the effectiveness of group and individual treatment formats.
authors.affiliation: Department of Psychology, University of Aarhus, Aarhus, Denmark.
authors.forename: H
authors.initials: H
authors.lastname: Jónsson
authors.forename: E
authors.initials: E
authors.lastname: Hougaard
mesh_terms: D000328:Adult; D015928:Cognitive Behavioral Therapy / Q000379:methods*; D005260:Female; D006801:Humans; D008297:Male; D009771:Obsessive-Compulsive Disorder / Q000628:therapy*; D011615:Psychotherapy, Group / Q000379:methods*; D016032:Randomized Controlled Trials as Topic