title: A pilot validation of a modified Illness Perceptions Questionnaire designed to predict response to cognitive therapy for psychosis.
abstract: OBJECTIVE
  Clinical responsiveness to cognitive behavioural therapy for psychosis (CBTp) varies. Recent research has demonstrated that illness perceptions predict active engagement in therapy, and, thereby, better outcomes. In this study, we aimed to investigate the psychometric properties of a modification of the Illness Perceptions Questionnaire (M-IPQ) designed to predict response following CBTp.
  
  
  METHODS
  Fifty-six participants with persistent, distressing delusions completed the M-IPQ; forty before a brief CBT intervention targeting persecutory ideation and sixteen before and after a control condition. Additional predictors of outcome (delusional conviction, symptom severity and belief inflexibility) were assessed at baseline. Outcomes were assessed at baseline and at follow-up four to eight weeks later.
  
  
  RESULTS
  The M-IPQ comprised two factors measuring problem duration and therapy-specific perceptions of Cure/Control. Associated subscales, formed by summing the relevant items for each factor, were reliable in their structure. The Cure/Control subscale was also reliable over time; showed convergent validity with other predictors of outcome; predicted therapy outcomes; and differentially predicted treatment effects.
  
  
  CONCLUSIONS
  We measured outcome without an associated measure of engagement, in a small sample. Findings are consistent with hypothesis and existing research, but require replication in a larger, purposively recruited sample.
  
  
  CONCLUSIONS
  The Cure/Control subscale of the M-IPQ shows promise as a predictor of response to therapy. Specifically targeting these illness perceptions in the early stages of cognitive behavioural therapy may improve engagement and, consequently, outcomes.
authors.affiliation: King's College London, Institute of Psychiatry, Department of Psychology, PO77, De Crespigny Park, Denmark Hill, London SE5 8AF, UK. Electronic address: Elena.marcus@kcl.ac.uk.
authors.forename: Elena
authors.initials: E
authors.lastname: Marcus
authors.affiliation: King's College London, Institute of Psychiatry, Department of Psychology, PO77, De Crespigny Park, Denmark Hill, London SE5 8AF, UK. Electronic address: philippa.garety@kcl.ac.uk.
authors.forename: Philippa
authors.initials: P
authors.lastname: Garety
authors.affiliation: King's College London, Institute of Pharmaceutical Science, 5th Floor Franklin Wilkins Building, 150 Stamford Street, London SE1 9NH, UK. Electronic address: John.weinman@kcl.ac.uk.
authors.forename: John
authors.initials: J
authors.lastname: Weinman
authors.affiliation: Centre for Biostatistics, Institute of Population Health, The University of Manchester, Manchester Academic Health Science Centre, 4.304 Jean McFarlane Building, Oxford Road, Manchester M13 9PL, UK. Electronic address: Richard.emsley@manchester.ac.uk.
authors.forename: Richard
authors.initials: R
authors.lastname: Emsley
authors.affiliation: Centre for Biostatistics, Institute of Population Health, The University of Manchester, Manchester Academic Health Science Centre, 4.304 Jean McFarlane Building, Oxford Road, Manchester M13 9PL, UK. Electronic address: graham.dunn@manchester.ac.uk.
authors.forename: Graham
authors.initials: G
authors.lastname: Dunn
authors.affiliation: Division of Psychiatry, University College, London, 67-73 Riding House Street, London W1W 7EJ, UK. Electronic address: P.bebbington@ucl.ac.uk.
authors.forename: Paul
authors.initials: P
authors.lastname: Bebbington
authors.affiliation: University of Oxford, Department of Psychiatry, Warneford Hospital, Oxford OX3 7JX, UK. Electronic address: Daniel.freeman@psych.ox.ac.uk.
authors.forename: Daniel
authors.initials: D
authors.lastname: Freeman
authors.affiliation: King's College London, Institute of Psychiatry, Department of Psychology, PO77, De Crespigny Park, Denmark Hill, London SE5 8AF, UK. Electronic address: Elizabeth.kuipers@kcl.ac.uk.
authors.forename: Elizabeth
authors.initials: E
authors.lastname: Kuipers
authors.affiliation: School of Psychology, University of Sussex, Pevensey Building, Falmer BN1 9QH, UK. Electronic address: D.Fowler@sussex.ac.uk.
authors.forename: David
authors.initials: D
authors.lastname: Fowler
authors.affiliation: King's College London, Institute of Psychiatry, Department of Psychology, PO77, De Crespigny Park, Denmark Hill, London SE5 8AF, UK. Electronic address: Amy.hard@kcl.ac.uk.
authors.forename: Amy
authors.initials: A
authors.lastname: Hardy
authors.affiliation: King's College London, Institute of Psychiatry, Department of Psychology, PO77, De Crespigny Park, Denmark Hill, London SE5 8AF, UK. Electronic address: Helen.waller@kcl.ac.uk.
authors.forename: Helen
authors.initials: H
authors.lastname: Waller
authors.affiliation: King's College London, Institute of Psychiatry, Department of Psychology, PO77, De Crespigny Park, Denmark Hill, London SE5 8AF, UK. Electronic address: Suzanne.Jolley@kcl.ac.uk.
authors.forename: Suzanne
authors.initials: S
authors.lastname: Jolley
mesh_terms: D000328:Adult; D002388:Catastrophic Illness / Q000523:psychology / Q000534:rehabilitation; D015928:Cognitive Behavioral Therapy / Q000379:methods*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010465:Perception / Q000502:physiology*; D010865:Pilot Projects; D011237:Predictive Value of Tests; D011569:Psychiatric Status Rating Scales; D011618:Psychotic Disorders / Q000523:psychology* / Q000534:rehabilitation*; D015203:Reproducibility of Results; D011795:Surveys and Questionnaires; D016896:Treatment Outcome
keywords: CBT; Engagement; IPQ; Schizophrenia; Therapy outcome