title: Exploring rationality in schizophrenia.
abstract: BACKGROUND
  Empirical studies of rationality (syllogisms) in patients with schizophrenia have obtained different results. One study found that patients reason more logically if the syllogism is presented through an unusual content.
  
  
  OBJECTIVE
  To explore syllogism-based rationality in schizophrenia.
  
  
  METHODS
  Thirty-eight first-admitted patients with schizophrenia and 38 healthy controls solved 29 syllogisms that varied in presentation content (ordinaryv.unusual) and validity (validv.invalid). Statistical tests were made of unadjusted and adjusted group differences in models adjusting for intelligence and neuropsychological test performance.
  
  
  RESULTS
  Controls outperformed patients on all syllogism types, but the difference between the two groups was only significant for valid syllogisms presented with unusual content. However, when adjusting for intelligence and neuropsychological test performance, all group differences became non-significant.
  
  
  CONCLUSIONS
  When taking intelligence and neuropsychological performance into account, patients with schizophrenia and controls perform similarly on syllogism tests of rationality.
  
  
  BACKGROUND
  None.
  © The Royal College of Psychiatrists 2015. This is an open access article distributed under the terms of the Creative Commons Non-Commercial, No Derivatives (CC BY-NC-ND) licence.
authors.affiliation: , MSc, PhD, Psychiatric Center Hvidovre & Glostrup Forensic Psychiatric Department, University of Copenhagen, Denmark.
authors.forename: Rasmus
authors.initials: R
authors.lastname: Revsbech
authors.affiliation: , MSc, Department of Public Health and Center for Healthy Aging, University of Copenhagen, Denmark.
authors.forename: Erik Lykke
authors.initials: EL
authors.lastname: Mortensen
authors.affiliation: , BSc, PhD, MBBS, MRCPsych, Institute of Psychiatry, Psychology and Neuroscience, Department of Psychological Medicine, Weston Education Centre, UK.
authors.forename: Gareth
authors.initials: G
authors.lastname: Owen
authors.affiliation: , MD, PhD, Department of Psychiatric Research, Region Zealand, Denmark.
authors.forename: Julie
authors.initials: J
authors.lastname: Nordgaard
authors.affiliation: , MD, Psychiatric Center Hvidovre, Denmark.
authors.forename: Lennart
authors.initials: L
authors.lastname: Jansson
authors.affiliation: , MSc, Institute of Preventive Medicine, Bispebjerg and Frederiksberg Hospital, The Capital Region, Denmark.
authors.forename: Ditte
authors.initials: D
authors.lastname: Sæbye
authors.affiliation: , MSc, PhD, Unit of Medical Psychology, Institute of Public Health, University of Copenhagen, Denmark.
authors.forename: Trine
authors.initials: T
authors.lastname: Flensborg-Madsen
authors.affiliation: , MD, Dr Med, Psychiatric Center Hvidovre, Center for Subjectivity Research, University of Copenhagen, Denmark.
authors.forename: Josef
authors.initials: J
authors.lastname: Parnas