Positive memory training for the treatment of depression in schizophrenia: A randomised controlled trial

Around half of people diagnosed with schizophrenia suffer from co-morbid depression, yet there are no evidence-based psychological treatments to target this presentation. Participants were aged 18–65 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 at 3-month, 6-month and 9-month 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. One hundred participants 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). To our knowledge this is, to date, the largest powered randomised controlled trial focused on the psychological treatment of depression in people diagnosed with schizophrenia. Results indicate 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. •The largest randomised controlled trial of a psychological intervention for low mood in people diagnosed with schizophrenia.•Anti-depressants are associated with a small effect in this group.•High levels of treatment retention and a significant reduction in depression at the end of the 3-months of intervention.•Treatment effects diminish during the follow-up phase suggesting booster sessions may be beneficial.