A multicentre randomised controlled trial of guided self-help versus treatment as usual for depression for autistic adults

Autistic people are 3-4 times more likely to be affected by depression than the general population. Low-intensity psychosocial interventions drawing on behavioural activation principles are recommended as effective treatments for depression. There is currently no evidence supporting the use of such treatments for autistic people with depression. We plan to establish the clinical and cost effectiveness of an adapted low-intensity psychological intervention for depression in autistic adults. We will conduct a multi-centre, 2-group parallel randomised controlled trial (RCT) of Guided Self-Help (GSH) compared to treatment as usual (TAU) with an internal pilot phase and nested qualitative study. The GSH intervention developed for the RCT comprises materials for nine 45-minute individual sessions, based on behavioural activation principles, facilitated by a low-intensity therapist trained to support autistic adults in their use of the materials. Low-intensity therapists have foundation knowledge and training in cognitive behaviour therapy (CBT) protocols. We will recruit autistic adults (n=248) from NHS adult autism services, NHS community mental health services and social care/third sector services. Participants with a clinical autism diagnosis and current depression, defined as having a PHQ-9 score equal to or greater than 10, and who fully consent to participate will be included in the study. Participants will be randomised to either GSH or TAU. Outcome measurement will be at baseline and 4, 8- and 12-months post-randomisation, assessing depression symptoms, anxiety, quality of life and an economic evaluation. A self-report measure of depression, the Beck Depression Inventory-II (BDI-II) will be the primary outcome measure. The qualitative study will examine participant and therapist views and experiences of the intervention and the trial. Qualitative findings will identify factors that may impact upon the intervention acceptability and effectiveness and implementation. The study will have Patient and Public Involvement on the Trial Steering Committee. A Patient Advisory Group (PAG) will provide advice about the conduct of the trial from a patient perspective and support the research team in development of patient-facing resources, activities to foster participant connectedness with the study, dissemination activities throughout the study and co-production of therapist training resources to enable rapid dissemination of the intervention.