Components of therapy as mechanisms of change in cognitive therapy for people at risk of psychosis: analysis of the EDIE-2 trial

Clare Flach; Paul French; Graham Dunn; David Fowler; Andrew I Gumley; Max Birchwood; Suzanne L K Stewart; Anthony P Morrison

doi:10.1192/bjp.bp.114.153320

Components of therapy as mechanisms of change in cognitive therapy for people at risk of psychosis: analysis of the EDIE-2 trial

Br J Psychiatry. 2015 Aug;207(2):123-9. doi: 10.1192/bjp.bp.114.153320. Epub 2015 May 21.

Authors

Clare Flach¹, Paul French², Graham Dunn², David Fowler², Andrew I Gumley², Max Birchwood², Suzanne L K Stewart², Anthony P Morrison²

Affiliations

¹ Clare Flach, PhD, Centre for Biostatistics, Institute of Population Health, University of Manchester, Manchester; Paul French, PhD, Psychosis Research Unit, Greater Manchester West NHS Foundation Trust, Manchester, and Department of Psychological Sciences, Liverpool University, Liverpool; Graham Dunn, PhD, Centre for Biostatistics, Institute of Population Health, University of Manchester, Manchester; David Fowler, MSc, School of Psychology, University of Sussex, Brighton; Andrew I. Gumley, PhD, Institute of Health and Wellbeing, University of Glasgow, Glasgow; Max Birchwood, DSc, Division of Mental Health and Wellbeing, University of Warwick, Warwick; Suzanne L. K. Stewart, PhD, Department of Psychology, University of Chester, Chester; Anthony P. Morrison, ClinPsyD, Psychosis Research Unit, Greater Manchester West NHS Foundation Trust, and School of Psychological Sciences, University of Manchester, Manchester, UK clare.flach@lshtm.ac.uk.
² Clare Flach, PhD, Centre for Biostatistics, Institute of Population Health, University of Manchester, Manchester; Paul French, PhD, Psychosis Research Unit, Greater Manchester West NHS Foundation Trust, Manchester, and Department of Psychological Sciences, Liverpool University, Liverpool; Graham Dunn, PhD, Centre for Biostatistics, Institute of Population Health, University of Manchester, Manchester; David Fowler, MSc, School of Psychology, University of Sussex, Brighton; Andrew I. Gumley, PhD, Institute of Health and Wellbeing, University of Glasgow, Glasgow; Max Birchwood, DSc, Division of Mental Health and Wellbeing, University of Warwick, Warwick; Suzanne L. K. Stewart, PhD, Department of Psychology, University of Chester, Chester; Anthony P. Morrison, ClinPsyD, Psychosis Research Unit, Greater Manchester West NHS Foundation Trust, and School of Psychological Sciences, University of Manchester, Manchester, UK.

PMID: 25999337
DOI: 10.1192/bjp.bp.114.153320

Abstract

Background: Research suggests that the way in which cognitive therapy is delivered is an important factor in determining outcomes. We test the hypotheses in which the development of a shared problem list, use of case formulation, homework tasks and active intervention strategies will act as process variables.

Method: Presence of these components during therapy is taken from therapist notes. The direct and indirect effect of the intervention is estimated by an instrumental variable analysis.

Results: A significant decrease in the symptom score for case formulation (coefficient = -23, 95% CI -44 to -1.7, P = 0.036) and homework (coefficient = -0.26, 95% CI -0.51 to -0.001, P = 0.049) is found. Improvement with the inclusion of active change strategies is of borderline significance (coefficient = -0.23, 95% CI -0.47 to 0.005, P = 0.056).

Conclusions: There is a greater treatment effect if formulation and homework are involved in therapy. However, high correlation between components means that these may be indicators of overall treatment fidelity.

Publication types

Comparative Study
Multicenter Study
Randomized Controlled Trial
Research Support, Non-U.S. Gov't

MeSH terms

Adolescent
Adult
Cognitive Behavioral Therapy / methods*
Female
Humans
Male
Problem Solving
Psychomotor Performance
Psychotic Disorders / prevention & control*
Risk Factors
Treatment Outcome
Young Adult

Abstract

Publication types

MeSH terms

Grants and funding