Positive Memory Training for the Treatment of Depression in Schizophrenia: A Randomised Controlled Trial

Background: Around half of people diagnosed with schizophrenia suffer from co-morbid depression, yet there are no evidence-based psychological treatments to target this presentation. Methods: We did this single-blind, randomised controlled trial at two NHS Trusts. Participants were aged 18 to 65 years old, had a clinical diagnosis of schizophrenia or schizoaffective disorder and at least a mild level of depression. Participants were randomly assigned (1:1) to receive PoMeT or treatment as usual. PoMeT was delivered in up to 12 individual sessions within 3 months. We stratified randomisation by site and by severity of depression using randomised-permuted blocks. Assessments were carried out at baseline, 3-month, 6-month and 9-month by assessors who were blind to treatment allocation. The primary outcome was reduction in the symptoms of depression as measured by the BDI-II. Analysis was by intention-to-treat with linear mixed-effects models. The trial was registered with the ISRCTN registry, number 99485756. Findings: Between May 1, 2014 and February 1, 2016, there were 262 referrals for the study of whom 119 gave consent and were assessed for eligibility. Of these, 100 were eligible and were randomly assigned to either PoMeT (n=49) or treatment as usual (n=51). The reduction in BDI-II total score at 3 months was significantly greater for PoMeT than for treatment as usual (mean difference=4.33, SE=2.00, 95% CI 0.38 to 8.23; p=0.03). Interpretation: To our knowledge this is the first powered randomised controlled trial focused on the psychological treatment of depression in people diagnosed with schizophrenia. We have shown that a brief targeted intervention can reduce the symptoms of depression in the group. The main limitation of the study is the lack of an active control group which may contribute to an inflated treatment effect. Clinical Trial Number: The trial was registered with the ISRCTN registry, number 99485756. Funding Statement: This article presents independent research funded by the NIHR under its Research for Patient Benefit (RfPB) Programme (grant reference number PB-PG- 0712-28021). Declaration of Interests: The authors declare that there are no conflicts of interest. Ethics Approval Statement: The study was approved by the NHS Research Ethics Committee (reference 13/SC/0634) and the trial protocol has been published23 and registered (ISRCTN99485756).