Intensive cognitive behavioural therapy for obsessive-compulsive disorder: A systematic review and meta-analysis

• Intensive CBT is an effective treatment for youths and adults with OCD.
• A larger post-treatment effect was found for intensive compared to standard CBT.
• Similar effects were found for intensive and standard CBT at 3 month follow up.
• Findings are based on 17 trials of intensive CBT, of which only four are RCTs.

Despite promising results from intensive formats of cognitive-behavioural therapy (CBT) for obsessive-compulsive disorder (OCD) the format is rarely used. The aim of the study was to systematically review the literature within this area of research and provide a meta-analysis of the effectiveness of intensive CBT for youths or adults with OCD. The meta-analysis was based on 17 trials (11 adult and 6 youth) including a total of 646 participants. Large overall pre–post effect sizes (ES) of 2.44 (95% CI 2.03–2.85) for clinical ratings (n=16) and 1.23 (95% CI 1.01–1.45) for self-reports (n=5) were found (Hedges g). Based on two comparative nonrandomized studies and one RCT, a larger post-treatment effect of intensive treatment compared to standard weekly or twice weekly CBT was found (between group ES=0.39 (95% CI 0.05–0.74) for clinical ratings). This difference was no longer present at 3 month follow-up, mainly due to slight deterioration among patients who had received intensive CBT while patients from weekly conditions changed little. In sum, the meta-analysis indicates that intensive CBT is an effective treatment for youths and adults with OCD, and could be a promising format to enhance immediate treatment effects compared to standard CBT. Focus on how to maintain superior post-treatment effects of intensive CBT could be a promising research area.