Treating Unhelpful Suspicious Thoughts in teenagers (TRUST): A schools-based feasibility randomised controlled clinical trial for adolescents (16-18 years) with elevated paranoia

Background: There is increasing evidence that paranoia, exaggerated fears that others intend to cause the individual harm, is common in adolescents, with 20-30% reporting weekly paranoid beliefs1 2. In adolescents, paranoia is associated with decreasing self-esteem and well-being3, distress, social difficulties and poor functioning4. It can also be a precursor to severe future mental health problems5. There are no evidence-based psychological interventions specifically for the treatment of paranoia in adolescents6. Adolescents with paranoia typically access support only once it has reached persecutory thresholds, which risks it becoming entrenched and difficult to treat. This project is closely informed by collaboration with young people with lived experienced of paranoia, two of whom are co-applicants. Aims and objectives: We will assess the feasibility of conducting a schools-based interventionist-causal (IC)-RCT on a six-session psychological therapy ("TRUST") versus standard school support to reduce elevated paranoia in adolescents (N=40) not receiving care from NHS services. Research questions: (1) what number of screened adolescents are eligible and consent? (2) what is the level of engagement with and adherence to the intervention? (3) what retention and data quality rates can be achieved? (4) what estimates of effect sizes are present? (5) what are participants views on acceptability of the trial and treatment? (6) What is the range of services used by participants and which are likely to be the key cost drivers to consider for the main trial? (7) what is the plausible benefit to the NHS of the intervention and its impact on health-related quality of life? (8) what is the risk of contamination? Methods: A 22-month (rater blind) feasibility IC-RCT with nested mixed methods process evaluation will be conducted. Forty adolescents (16-18 years) with elevated paranoia will be randomised to standard care or standard care plus TRUST. TRUST is a novel psychological intervention designed to target mechanisms that underpin paranoia in adolescents, by reducing negative self/other beliefs and distressing paranoia-related imagery, and enhancing value-directed behaviour. We will examine post-treatment (10- and 18-week post-randomisation) data retention rates on the Revised Green et al. s Paranoid Thoughts Scale7 (R-GPTS). Consistent with the MRC Framework for process evaluation, qualitative methods will examine: what was implemented, how context affected implementation and outcomes, mechanisms of impact from the perspective of participant and acceptability. Timeline for delivery: Feasibility and acceptability data (within two-years), dissemination of findings, secure funding and developing treatment manual for definitive trial (two-five years), results from definitive trial, developing training resources and training workforce (five-seven years). Anticipated impact and dissemination: If the findings from the study suggest that a future trial is warranted, funding will be sought for a fully-powered RCT to establish clinical and cost-effectiveness. This future trial would include developing (with Educational Mental Health Practitioner (EMHP) consultation) a therapy manual and online EMHP training materials. Subsequent implementation of TRUST within secondary schools would generate benefits for adolescents experiencing paranoia (reduced distress), school populations (enhanced understanding) and CAMHS (reduced demand). De-stigmatising dissemination materials (videos, blogs, etc) will also be developed with our adolescent public patient involvement group.