Title: Group Mindfulness Based Therapy for distressing persecutory delusions: A pilot study for a randomised controlled trial.
Funder: Department of Health and Social Care

Abstract: Background There is increasing evidence showing the potential benefits of mindfulness for individuals with a diagnosis of Schizophrenia (Chadwick et al, 2005, 2009; Dannahy et al, 2011; Langer et al, 2012). However, research to date has focused on individuals who experience auditory hallucinations, and research is yet to examine the benefit and process of change of mindfulness for people with persecutory delusions. To date there are only 2 single case studies (demonstrating proof of concept) showing initial promise for mindfulness-based therapy (MBT) for reducing depression associated with persecutory delusions (Ellett, 2013). A more methodologically robust investigation of mindfulness for persecutory delusions is required; however, at this stage, a fully-powered RCT would not be a judicious use of public money as the key parameters for such a trial (e.g. effect size, recruitment and retention) are not known. Aims The research question for the full RCT is: Following the intervention, in comparison to participants receiving treatment as usual (TAU), participants receiving mindfulness-based therapy (plus TAU) will report significantly lower depression, better psychological health, significantly lower levels of distress, significantly lower amounts of rumination and significantly greater progress towards recovery. This full trial research question has informed the aims for this proposed pilot study. In order to address this research question in a full trial we first need to have: (a) a reasonable estimate of the between-group effect size on the primary outcome measure (depression), (b) an understanding of rates of recruitment and (c) a strategy to maximise retention - hence the need for this pilot study. Plan of investigation Participants will be randomised to receive either mindfulness-based therapy or treatment as usual. Mindfulness therapy, specifically adapted for people with distressing psychotic experience, will be delivered using our manusalised 12-session group protocol. This is consistent with the approach in other disorders including depression (Segal et al, 2002) and those who experience hearing voices (Chadwick et al, 2009). The primary outcome measure for the study is depression. Other outcomes that will be measured include quality of life, psychotic symptoms and progress towards recovery. In addition to measuring outcomes, we will also measure potential mechanisms of change, that is, the psychological processes that we expect to change more during MBT than during TAU. These will include rumination, avoidance and negative schema. If the pilot reveals a between-group effect size in favour of the mindfulness intervention, an application will then be made to HTA for a full randomised-controlled trial. Group-based mindfulness is a potentially resource-efficient therapy in comparison to individual therapy. Potential Benefits to Patients & the NHS This study will provide information for a full trial that will ascertain if group mindfulness therapy has the potential to reduce depression and distress, and improve psychological health for individuals with distressing persecutory delusions. Therefore, this pilot study and the full trial to follow have the potential to improve the lives of people living with distressing persecutory delusions and their families. The group-based nature of the mindfulness intervention has the potential to incur significant savings for the NHS, as this is a more cost-effective intervention than individual therapy. Our manualised 12-session group protocol is very clear and easy to follow, such that the intervention would be rolled out within the NHS if it is found to be effective.

Lay abstract: Many people with a diagnosis of Schizophrenia experience persecutory delusions, thinking that other people are intentionally trying to harm or kill them. Persecutory delusions are often associated with high levels of depression and distress. Psychological interventions that use mindfulness, a form of meditation, are being used to help people who experience mental health problems. Until recently, these interventions have rarely been made available to people with a diagnosis of Schizophrenia, despite the significant level of need within this group. Our research team have adapted mindfulness meditation for people who hear distressing voices and have developed a mindfulness-based group therapy. This therapy has been found to be beneficial as voice hearers reported reduced distress, and improved psychological health. However, very little research has been done to examine whether mindfulness-based therapies are helpful for people who experience persecutory delusions. This study will recruit approximately 40 individuals who experience persecutory delusions as their primary psychotic symptom. Half of the service users will receive mindfulness-based therapy offered in a group format over a 12-session period. The other half will receive the treatment they usually receive from their mental health teams, to determine whether the therapy group reduces depression and distress, improves psychological health and results in greater progress towards recovery. Before we can answer this question in a fully-sized trial we first need to conduct a pilot study, which will tell us: (a) the approximate difference in outcome between mindfulness and usual treatment, (b) how easily we can recruit to the study, and (c) how many people drop out. This information will allow us to know how many participants we need for the full trial, how long recruitment will take and how to reduce drop-out rates. Once we have this information we will apply for funding for the full trial.

Research activity codes: 6.6 PSYCHOLOGICAL AND BEHAVIOURAL
Health categories: MENTAL HEALTH