Background
Many patients suffering from schizophrenia spectrum disorders continue having distressing auditory hallucinations in spite of treatment with antipsychotic medication. The aim of this trial is to examine the effect of a targeted virtual reality therapy for persistent auditory hallucinations in individuals with psychosis. The trial explores whether this type of therapy can decrease the severity, frequency and distress of auditory hallucinations and, additionally, whether it can reduce clinical symptoms and enhance daily functioning in individuals with psychosis.

Methods
The study is a randomised, assessor-blinded parallel-group superiority clinical trial, allocating a total of 266 patients to either the experimental intervention or supportive counselling. The participants will be randomised to either (1) seven sessions of virtual reality therapy or (2) seven sessions of supportive counselling to be delivered within the first 12 weeks after inclusion in the study. All participants will be assessed at baseline and 12 and 24 weeks post-baseline. Independent assessors blinded to the treatment allocation will evaluate the outcome. The primary outcome is the level of auditory hallucinations measured with the Psychotic Symptoms Rating Scales (PSYRATS-AH) total score at the cessation of treatment at 12 weeks. Secondary outcomes are frequency of auditory hallucinations, the distress caused by auditory hallucinations, perceived voice power, patient acceptance of voices, patients’ ability to respond to voices in an assertive way and social and daily function.

Discussion
Promising evidence of the efficacy of this immersive virtual reality-based therapy for auditory hallucinations exist, but evidence needs to be established in a large, methodological rigorous trial. If the therapy proves to be beneficial in reducing the severity of refractory auditory hallucinations, a large group of patients with schizophrenia and related disorders could be the target group of this short-term psychotherapeutic intervention.