title: Reducing Delusional Conviction through a Cognitive-Based Group Training Game: A Multicentre Randomized Controlled Trial.
abstract: OBJECTIVE
  "Michael's game" (MG) 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 (MADS).
  
  
  METHODS
  We performed a parallel, assessor-blinded, randomized controlled superiority trial comparing treatment as usual plus participation in 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 randomized, 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.
authors.affiliation: Geneva University Hospitals, Geneva University , Geneva , Switzerland.
authors.forename: Yasser
authors.initials: Y
authors.lastname: Khazaal
authors.affiliation: Geneva University Hospitals, Geneva University , Geneva , Switzerland.
authors.forename: Anne
authors.initials: A
authors.lastname: Chatton
authors.affiliation: Geneva University Hospitals, Geneva University , Geneva , Switzerland.
authors.forename: Karen
authors.initials: K
authors.lastname: Dieben
authors.affiliation: Geneva University Hospitals, Geneva University , Geneva , Switzerland.
authors.forename: Philippe
authors.initials: P
authors.lastname: Huguelet
authors.affiliation: Geneva University Hospitals, Geneva University , Geneva , Switzerland.
authors.forename: Maria
authors.initials: M
authors.lastname: Boucherie
authors.affiliation: Geneva University Hospitals, Geneva University , Geneva , Switzerland.
authors.forename: Gregoire
authors.initials: G
authors.lastname: Monney
authors.affiliation: Service de Psychiatrie, CHU de Caen, Université de Caen Basse-Normandie, UMR6301 ISTCT, ISTS Team , Caen , France.
authors.forename: Laurent
authors.initials: L
authors.lastname: Lecardeur
authors.affiliation: Fribourg Network for Mental Health , Fribourg , Switzerland.
authors.forename: Virginie
authors.initials: V
authors.lastname: Salamin
authors.affiliation: Service de Psychiatrie Ambulatoire et de Réhabilitation du Pôle Rouen Rive Droite, Centre Hospitalier du Rouvray, Centre de Jour Saint-Gervais , Rouen , France.
authors.forename: Fethi
authors.initials: F
authors.lastname: Bretel
authors.affiliation: Centre Psychosocial , Biel , Switzerland.
authors.forename: Silke
authors.initials: S
authors.lastname: Azoulay
authors.affiliation: MIDI Foyer SISP EMS , Yverdon Les Bains , Switzerland.
authors.forename: Elodie
authors.initials: E
authors.lastname: Pesenti
authors.affiliation: La Borde, Foyer SISP EMS , Lausanne , Switzerland.
authors.forename: Raoul
authors.initials: R
authors.lastname: Krychowski
authors.affiliation: La Borde, Foyer SISP EMS , Lausanne , Switzerland.
authors.forename: Andreia
authors.initials: A
authors.lastname: Costa Prata
authors.affiliation: Geneva University Hospitals, Geneva University , Geneva , Switzerland.
authors.forename: Javier
authors.initials: J
authors.lastname: Bartolomei
authors.affiliation: Service de Psychiatrie, CHU de Caen, Université de Caen Basse-Normandie, UMR6301 ISTCT, ISTS Team , Caen , France.
authors.forename: Perrine
authors.initials: P
authors.lastname: Brazo
authors.affiliation: Centre Medico-Psychologique B, Centre Hospitalier Universitaire , Clermont-Ferrand , France.
authors.forename: Alexei
authors.initials: A
authors.lastname: Traian
authors.affiliation: Service de Psychiatrie, Centre Hospitalier de Vichy , Vichy , France.
authors.forename: Thomas
authors.initials: T
authors.lastname: Charpeaud
authors.affiliation: Unité Mobile de Psychiatrie, Centre Hospitalier Princess Grace , Monaco , Monaco.
authors.forename: Elodie
authors.initials: E
authors.lastname: Murys
authors.affiliation: Léon-Jean Grégory Hospital , Thuir , France.
authors.forename: Florent
authors.initials: F
authors.lastname: Poupart
authors.affiliation: CRESOP, Centre Hospitalier le Vinatier , Bron , France.
authors.forename: Serge
authors.initials: S
authors.lastname: Rouvière
authors.affiliation: Geneva University Hospitals, Geneva University , Geneva , Switzerland.
authors.forename: Daniele
authors.initials: D
authors.lastname: Zullino
authors.affiliation: Laboratory of Epidemiology and Social Psychiatry, IRCCS 'Mario Negri' Institute for Pharmacological Research , Milan , Italy.
authors.forename: Alberto
authors.initials: A
authors.lastname: Parabiaghi
authors.affiliation: CRESOP, Centre Hospitalier le Vinatier , Bron , France ; EA 4615, Université de Lyon , Lyon , France ; Université Lyon 1 , Lyon , France.
authors.forename: Mohamed
authors.initials: M
authors.lastname: Saoud
authors.affiliation: School of Nursing Sciences La Source, University of Applied Sciences and Arts of Western Switzerland , Lausanne , Switzerland.
authors.forename: Jérôme
authors.initials: J
authors.lastname: Favrod
keywords: cognitive therapy; game; hypothetical reasoning; psychotherapy; psychotic disorders; randomized controlled study; schizophrenia