The University of Southampton
University of Southampton Institutional Repository

Effects of cognitive behaviour therapy for worry on persecutory delusions in patients with psychosis (WIT): a parallel, single-blind, randomised controlled trial with a mediation analysis

Effects of cognitive behaviour therapy for worry on persecutory delusions in patients with psychosis (WIT): a parallel, single-blind, randomised controlled trial with a mediation analysis
Effects of cognitive behaviour therapy for worry on persecutory delusions in patients with psychosis (WIT): a parallel, single-blind, randomised controlled trial with a mediation analysis

BACKGROUND: Worry might be a contributory causal factor in the occurrence of persecutory delusions in patients with psychotic disorders. Therefore we postulated that reducing worry with cognitive behaviour therapy (CBT) would reduce persecutory delusions.

METHODS: For our two-arm, assessor-blinded, randomised controlled trial (Worry Intervention Trial [WIT]), we recruited patients aged 18-65 years with persistent persecutory delusions but non-affective psychosis from two centres: the Oxford Health National Health Service (NHS) Foundation Trust (Oxford, UK) and the Southern Health NHS Foundation Trust (Southampton, UK). The key inclusion criteria for participants were a score of at least 3 on the Psychotic Symptoms Rating Scale (PSYRATS) denoting a current persecutory delusion; that the delusion had persisted for at least 3 months; a clinical diagnosis of schizophrenia, schizoaffective disorder, or delusional disorder; and a clinically significant level of worry. We randomly assigned (1:1) eligible patients, using a randomly permuted block procedure with variable block sizes and division by four strata, to either six sessions of worry-reduction CBT intervention done over 8 weeks added to standard care (the CBT-intervention group), or to standard care alone (the control group). The assessors were masked to patient allocations and did their assessments at week 0 (baseline), 8 weeks (end of treatment), and 24 weeks, follow-up. The primary outcomes were worry measured by the Penn State Worry Questionnaire (PSWQ) and delusions measured by the PSYRATS-delusion scale; we did the analyses in the intention-to-treat population, and also did a planned mediation analysis. This trial is registered with the ISRCTN Registry (number ISRCTN23197625) and is closed to new participants.

FINDINGS: From Nov 1, 2011, to Sept 9, 2013, we recruited 150 eligible participants and randomly assigned 73 to the CBT intervention group, and 77 to the control group. 143 patients (95%) provided primary outcome follow-up data. Compared with standard care alone, at 8 weeks the CBT intervention significantly reduced worry (mean difference 6·35 [SE 1·56] PSWQ units, 95% CI 3·30-9·40; p<0·001) and persecutory delusions (2·08 [SE 0·73] PSYRATS units, 95% CI 0·64-3·51; p=0·005). The reductions were maintained to 24 weeks follow-up. The mediation analysis suggested that the change in worry accounted for 66% of the change in delusion. No patients died or were admitted to secure units during our study. Six suicide attempts (two in the CBT intervention group, and four in the control group) and two serious violent incidents (one in each group) were noted, but no adverse events were deemed related to the treatments or the assessments.

INTERPRETATION: To our knowledge, this is the first large trial focused on persecutory delusions. We have shown that long-standing delusions were significantly reduced by a brief intervention targeted on worry, although the limitations for our study include no determination of the key elements within the intervention. Our results suggest that worry might cause paranoia, and that worry intervention techniques might be a beneficial addition to the standard treatment of psychosis.

FUNDING: Efficacy and Mechanism Evaluation programme, which is a UK Medical Research Council and National Institute of Health Research partnership.

Adolescent, Adult, Aged, Anxiety, Cognitive Therapy, Delusions, Female, Humans, Male, Middle Aged, Paranoid Disorders, Psychiatric Status Rating Scales, Psychotic Disorders, Schizophrenia, Schizophrenia, Paranoid, Single-Blind Method, Journal Article, Randomized Controlled Trial, Research Support, Non-U.S. Gov't
2215-0366
305-313
Freeman, Daniel
b90a2f85-f05c-40e8-a592-e1545fae654c
Dunn, Graham
ffc12c0e-b002-43fd-bdf7-60e17f4b4871
Startup, Helen
a1d210d2-a4d7-4c2c-bb75-32338bb5eef4
Pugh, Katherine
edab0db5-0c6e-4933-8cab-25fd48ebe3a9
Cordwell, Jacinta
fe80e3a7-e1d4-41b3-bb5d-fdb797a9e741
Mander, Helen
0b702eaf-3a23-4e01-ae92-19941c26b9e8
Černis, Emma
f368b917-41df-4168-b33f-538ce2c05a00
Wingham, Gail
238517f5-1c8f-4dac-8ea5-626ade856b96
Shirvell, Katherine
4f9dfa36-cc31-41ad-ad3a-3f38591506a2
Kingdon, David
14cdc422-10b4-4b2d-88ec-24fde5f4329b
Freeman, Daniel
b90a2f85-f05c-40e8-a592-e1545fae654c
Dunn, Graham
ffc12c0e-b002-43fd-bdf7-60e17f4b4871
Startup, Helen
a1d210d2-a4d7-4c2c-bb75-32338bb5eef4
Pugh, Katherine
edab0db5-0c6e-4933-8cab-25fd48ebe3a9
Cordwell, Jacinta
fe80e3a7-e1d4-41b3-bb5d-fdb797a9e741
Mander, Helen
0b702eaf-3a23-4e01-ae92-19941c26b9e8
Černis, Emma
f368b917-41df-4168-b33f-538ce2c05a00
Wingham, Gail
238517f5-1c8f-4dac-8ea5-626ade856b96
Shirvell, Katherine
4f9dfa36-cc31-41ad-ad3a-3f38591506a2
Kingdon, David
14cdc422-10b4-4b2d-88ec-24fde5f4329b

Freeman, Daniel, Dunn, Graham, Startup, Helen, Pugh, Katherine, Cordwell, Jacinta, Mander, Helen, Černis, Emma, Wingham, Gail, Shirvell, Katherine and Kingdon, David (2015) Effects of cognitive behaviour therapy for worry on persecutory delusions in patients with psychosis (WIT): a parallel, single-blind, randomised controlled trial with a mediation analysis. Lancet Psychiatry, 2 (4), 305-313. (doi:10.1016/S2215-0366(15)00039-5).

Record type: Article

Abstract

BACKGROUND: Worry might be a contributory causal factor in the occurrence of persecutory delusions in patients with psychotic disorders. Therefore we postulated that reducing worry with cognitive behaviour therapy (CBT) would reduce persecutory delusions.

METHODS: For our two-arm, assessor-blinded, randomised controlled trial (Worry Intervention Trial [WIT]), we recruited patients aged 18-65 years with persistent persecutory delusions but non-affective psychosis from two centres: the Oxford Health National Health Service (NHS) Foundation Trust (Oxford, UK) and the Southern Health NHS Foundation Trust (Southampton, UK). The key inclusion criteria for participants were a score of at least 3 on the Psychotic Symptoms Rating Scale (PSYRATS) denoting a current persecutory delusion; that the delusion had persisted for at least 3 months; a clinical diagnosis of schizophrenia, schizoaffective disorder, or delusional disorder; and a clinically significant level of worry. We randomly assigned (1:1) eligible patients, using a randomly permuted block procedure with variable block sizes and division by four strata, to either six sessions of worry-reduction CBT intervention done over 8 weeks added to standard care (the CBT-intervention group), or to standard care alone (the control group). The assessors were masked to patient allocations and did their assessments at week 0 (baseline), 8 weeks (end of treatment), and 24 weeks, follow-up. The primary outcomes were worry measured by the Penn State Worry Questionnaire (PSWQ) and delusions measured by the PSYRATS-delusion scale; we did the analyses in the intention-to-treat population, and also did a planned mediation analysis. This trial is registered with the ISRCTN Registry (number ISRCTN23197625) and is closed to new participants.

FINDINGS: From Nov 1, 2011, to Sept 9, 2013, we recruited 150 eligible participants and randomly assigned 73 to the CBT intervention group, and 77 to the control group. 143 patients (95%) provided primary outcome follow-up data. Compared with standard care alone, at 8 weeks the CBT intervention significantly reduced worry (mean difference 6·35 [SE 1·56] PSWQ units, 95% CI 3·30-9·40; p<0·001) and persecutory delusions (2·08 [SE 0·73] PSYRATS units, 95% CI 0·64-3·51; p=0·005). The reductions were maintained to 24 weeks follow-up. The mediation analysis suggested that the change in worry accounted for 66% of the change in delusion. No patients died or were admitted to secure units during our study. Six suicide attempts (two in the CBT intervention group, and four in the control group) and two serious violent incidents (one in each group) were noted, but no adverse events were deemed related to the treatments or the assessments.

INTERPRETATION: To our knowledge, this is the first large trial focused on persecutory delusions. We have shown that long-standing delusions were significantly reduced by a brief intervention targeted on worry, although the limitations for our study include no determination of the key elements within the intervention. Our results suggest that worry might cause paranoia, and that worry intervention techniques might be a beneficial addition to the standard treatment of psychosis.

FUNDING: Efficacy and Mechanism Evaluation programme, which is a UK Medical Research Council and National Institute of Health Research partnership.

Text
14TLP0548_Freeman_FINAL.pdf - Accepted Manuscript
Available under License Creative Commons Attribution.
Download (907kB)

More information

e-pub ahead of print date: 4 March 2015
Published date: April 2015
Keywords: Adolescent, Adult, Aged, Anxiety, Cognitive Therapy, Delusions, Female, Humans, Male, Middle Aged, Paranoid Disorders, Psychiatric Status Rating Scales, Psychotic Disorders, Schizophrenia, Schizophrenia, Paranoid, Single-Blind Method, Journal Article, Randomized Controlled Trial, Research Support, Non-U.S. Gov't
Organisations: Faculty of Medicine

Identifiers

Local EPrints ID: 374822
URI: https://eprints.soton.ac.uk/id/eprint/374822
ISSN: 2215-0366
PURE UUID: 49ccc1e4-d61e-4ac1-af58-01f71791a763

Catalogue record

Date deposited: 06 Mar 2015 13:59
Last modified: 19 Jul 2019 20:51

Export record

Altmetrics

Contributors

Author: Daniel Freeman
Author: Graham Dunn
Author: Helen Startup
Author: Katherine Pugh
Author: Jacinta Cordwell
Author: Helen Mander
Author: Emma Černis
Author: Gail Wingham
Author: Katherine Shirvell
Author: David Kingdon

University divisions

Download statistics

Downloads from ePrints over the past year. Other digital versions may also be available to download e.g. from the publisher's website.

View more statistics

Atom RSS 1.0 RSS 2.0

Contact ePrints Soton: eprints@soton.ac.uk

ePrints Soton supports OAI 2.0 with a base URL of https://eprints.soton.ac.uk/cgi/oai2

This repository has been built using EPrints software, developed at the University of Southampton, but available to everyone to use.

We use cookies to ensure that we give you the best experience on our website. If you continue without changing your settings, we will assume that you are happy to receive cookies on the University of Southampton website.

×