Metacognitive therapy vs. eye movement desensitization and reprocessing for posttraumatic stress disorder: Study protocol for a randomized superiority trial

Background: The psychological treatment of choice for patients with severe posttraumatic stress disorder (PTSD) is cognitive behavioural exposure therapy or Eye Movement Desensitisation Reprocessing (EMDR). Whilst these are the most effective treatments, approximately 30-45% of the patients show no significant improvements and follow-up data are sparse. Furthermore, a proportion of patients with severe trauma does not benefit or avoid exposure therapy due to the potential to overwhelm them. Therefore, it is necessary to search for effective methods that do not require exposure. Metacognitive therapy (MCT), a recent treatment approach to PTSD that does not require exposure, has potential strong treatment effects but so far a comparison with EMDR has not been made. Methods/design: This study is a two-arm, parallel, randomized, superiority trial comparing the effectiveness of MCT with EMDR. One hundred patients with a primary diagnosis of chronic PTSD will be included and will receive 12 sessions of one of the treatments. The primary outcome is severity of PTSD symptoms assessed with the Posttraumatic Diagnostic Scale (PDS) measured post-treatment (3 months). Secondary outcomes include symptom severity (PDS) and measures of anxiety, depression, metacognitive beliefs at 3-month and 12-month follow up. Discussion: This randomized study is the first to compare MCT with EMDR with 12-month follow-up. The study will indicate the comparative effectiveness of MCT against EMDR and the stability of effects when delivered in an outpatient clinical setting. Trial registration: ClinicalTrials.gov, NCT01955590. Registered on 24 September 2013.