The Street Smart Group: A Feasibility Trial of a Group Intervention Targeting Anxiety Processes in Paranoia

People with a schizophrenia spectrum diagnosis often experience distressing worries or beliefs about other people intending to cause them harm (also known as paranoia). Paranoid beliefs are associated with significant distress and disruption to the person's life. This results in high use of services and costs to mental health providers.

The National Institute of Clinical Excellence recommends that cognitive behavioural therapy for psychosis (CBTp) is offered to everybody with a schizophrenia spectrum psychosis. The latest meta analyses report improved outcomes, and reduced inpatient stays following CBTp, making it a cost effective intervention.

Although improved outcomes have been obtained by therapies, CBTp has only small to moderate effects on paranoid beliefs. Further, training therapists to competently deliver CBTp is intensive, expensive and takes up to a year. CBTp is therefore not widely available to service users, resulting in inequalities in access to care.

The investigators are seeking to improve outcomes and accessibility of CBTp for people with distressing, paranoid beliefs. The proposed research programme aims to conduct a feasibility study of a brief therapeutic group intervention, aimed at targeting and improving anxiety processes which are causally implicated in paranoia.

The investigators have preliminary evidence indicating that the pilot intervention delivered in an individual format, with interactive multimedia content, reduced distressing beliefs and improved coping (Freeman et al, 2014). Participants also reported they found the interventions acceptable, enjoyable and useful. Based on these results, the investigators have further developed the intervention and the current study proposes to evaluate the modified intervention delivered in a group format. A pilot randomised controlled trial (RCT) of the novel group intervention will be conducted to inform its further development and to estimate key parameters required to plan a larger trial.

The feasibility and efficacy of the therapy will be investigated in a randomised controlled design (n = 35) with a between-groups longitudinal design to compare key outcomes between people who do and do not receive the intervention and to estimate key trial parameters. Participants will be randomised to either an immediate intervention or a delayed intervention condition (in which they are offered the intervention after completing all assessments) using a 2:1 ratio. Participants will be randomised after completing baseline measures using an independent web-based randomisation service. The researchers will be delivering the intervention and therefore will not be blind to group allocation. Participants will be recruited from community mental health teams and standalone psychology services in the South London and Maudsley NHS Foundation Trust.

As this is a pilot study, the statistical analysis will be mainly descriptive in nature, aiming to provide estimates of key trial parameters and to inform power calculations for a future larger scale trial. A description of the sample will be presented using means and standard deviations for continuous data, or medians and interquartile range if data are skewed. Frequencies and proportions will be used to analyse categorical variables. Feasibility of trial procedures will be assessed using proportions of predetermined parameters and their estimated 95% confidence intervals (CIs). Population variances for future power calculations will be determined using the upper 80th percentile of confidence intervals around the estimated population variance, as recommended by Browne (1995).