AUTHOR=Khazaal Yasser , Chatton Anne , Dieben Karen , Huguelet Philippe , Boucherie Maria , Monney Gregoire , Lecardeur Laurent , Salamin Virginie , Bretel Fethi , Azoulay Silke , Pesenti Elodie , Krychowski Raoul , Costa Prata Andreia , Bartolomei Javier , Brazo Perrine , Traian Alexei , Charpeaud Thomas , Murys Elodie , Poupart Florent , Rouvière Serge , Zullino Daniele , Parabiaghi Alberto , Saoud Mohamed , Favrod Jérôme TITLE=Reducing Delusional Conviction through a Cognitive-Based Group Training Game: A Multicentre Randomized Controlled Trial JOURNAL=Frontiers in Psychiatry VOLUME=Volume 6 - 2015 YEAR=2015 URL=https://www.frontiersin.org/journals/psychiatry/articles/10.3389/fpsyt.2015.00066 DOI=10.3389/fpsyt.2015.00066 ISSN=1664-0640 ABSTRACT=Abstract Objective: “Michael’s Game” is a card game targeting the ability to generate alternative hypotheses to explain a given experience. The main objective was to evaluate the effect of MG on delusional conviction as measured by the primary study outcome: the change in scores on the conviction subscale of the Peters Delusions Inventory (PDI-21). Other variables of interest were the change in scores on the distress and preoccupation subscales of the PDI-21, the Brief Psychiatric Rating Scale, the Beck Cognitive Insight Scale, and belief flexibility assessed with the Maudsley Assessment of Delusions Schedule. Methods: We performed a parallel, assessor-blinded, randomised controlled superiority trial comparing treatment as usual plus participation in Michael’s Game (MG) with treatment as usual plus being on a waiting list (TAU) in a sample of adult outpatients with psychotic disorders and persistent positive psychotic symptoms at inclusion. Results: The 172 participants were randomised, with 86 included in each study arm. Assessments were performed at inclusion (T1: baseline), at 3 months (T2: post-treatment), and at 6 months after the second assessment (T3: follow-up). At T2, a positive treatment effect was observed on the primary outcome, the PDI-21 conviction subscale (p=0.005). At T3, a sustained effect was observed for the conviction subscale (p=0.002). Further effects were also observed at T3 on the PDI-21 distress (p=0.002) and preoccupation subscales (p=0.001), as well as on one of the MADS measures of belief flexibility (“anything against the belief”) (p=0.001). Conclusions: The study demonstrated some significant beneficial effect of MG. http://www.controlled-trials.com/ISRCTN37178153/ Funding: Swiss National Science Foundation Grant 32003B-121038