Developing immersive virtual exposures for obsessive-compulsive disorder – Protocol for a Randomised, Controlled, Proof-of-Concept Feasibility Trial

Background Exposure and response prevention (ERP) is the gold-standard psychological treatment for obsessive compulsive disorder (OCD). However, its delivery typically requires frequent therapist availability and repeated patient travel to treatment settings, which limits accessibility. In addition, the idiosyncratic nature of obsessive-compulsive symptoms presents challenges for conducting effective exposures within the time and material constraints of traditional clinical environments. Virtual reality (VR)-based interventions may help address these limitations. This study aims to assess the feasibility of a novel approach that uses generative artificial intelligence (GenAI) to create personalised, immersive 3D exposure environments tailored to individual patient fears. Methods This is a randomised controlled feasibility study with three parallel arms and an assessor-blinded design. Forty-five adults with a primary diagnosis of OCD and moderate to extremely severe symptoms will be randomly allocated in a 1:1:1 ratio to OCD-related exposure administered via VR environments, neutral VR environments, or OCD-related stimuli presented on a widescreen display. Participants will complete a baseline assessment and an GenAI-based stimulus titration session, followed by two therapist-led ERP sessions that frame five consecutive days of asynchronous exposure (exposure blocks/scenarios that are not therapist-led ERP). The intervention uses text-to-image synthesis, image conversion into 3D Gaussian Splatting environments, and delivery via VR headsets or widescreen display. Primary feasibility outcomes include recruitment and retention rates, data completeness, and adherence to the asynchronous exposure protocol. Secondary outcomes include progression through personalised exposure hierarchies, physiological reactivity (electrodermal activity and heart rate), cybersickness, and subjective distress measures. Discussion This study will determine whether AI-driven VR exposure is feasible, safe, and acceptable for adults with OCD. The proposed approach standardises the process of content generation while personalising the actual stimuli, towards leveraging technology to ensure the personalised needs of these patients are more effectively met. Results can inform the refinement of the intervention and the study procedures, including sample size estimation for a future randomised controlled trial. If successful, this methodology could have the potential to improve scalability, reduce costs, and enhance the ecological validity of exposure therapy while maintaining clinical efficacy. Trial registration ISRCTN13869986. Registered 29 December 2025. Prospectively registered.