Virtual Reality Therapy for Voice Hearing (VR-VOICES): a Randomized Controlled Trial

Rationale: Auditory verbal hallucinations (AVH) - hearing voices that others cannot hear - are common in mental illnesses. For many people AVH are distressing, disabling and persistent, despite medication. Current psychological interventions show low to medium effects. Preliminary studies suggest that an innovative empowering psychological therapy using computer simulations representing the AVH (avatars) can be effective for reducing AVH distress and frequency. Virtual reality (VR) has the potential to improve this treatment. Therefore, we developed a novel VR treatment for this problem. In this study, the effect of this treatment will be investigated.

Objective: To test the effect of a novel VR treatment for AVH (VR-VOICES) on distress and frequency of AVH in patients with a psychiatric disorder. Furthermore, to investigate the effect of VR-VOICES on clinical symptoms, quality of life, and healthcare costs of the treatment.

Study design: Single-blind randomized controlled intervention trial (RCT) with two arms: VR-VOICES as intervention and treatment as usual (TAU) as a control condition.

Study population: Patients with a DSM-5 diagnosis who have experienced distressing AVH for at least 3 months, who are 16 years or older (N=112).

Intervention:

* VR-VOICES intervention: 7-10 sessions of 45-60 minutes of individual VR assisted therapy and two booster sessions, in addition to TAU. Participants allocated to VR-VOICES create together with their therapist a VR digital representation (avatar with face, body and voice) of the voice that bothers them most. Patients have dialogues with the avatar, voiced by the therapist. As indicated in the treatment protocol, over the sessions the avatar will become less hostile and the participant will gain more power and resilience over the avatar.
* Control: TAU as described in the current Dutch treatment guidelines, which generally exists of pharmacological treatment, supportive counseling, and psychological interventions such as CBT and coping strategies.

Main study parameters/endpoints: Assessments will be obtained at baseline, within some VR-VOICES sessions, posttreatment (12 weeks after baseline), and at 6-month follow-up. Primary outcome: severity of AVH (total score on the auditory hallucinations scale of the PSYRATS) at post-treatment. Secondary outcomes: in-depth characteristics of AVH such as the frequency, voice impact, beliefs about voices, power relative to voices, levels of anxiety, distress and impact on daily life as measured with questionnaires and diary assessments in the flow of daily life. Other secondary outcomes include clinical symptoms, cost-effectiveness and quality of life.

Eligibility Criteria:
Inclusion Criteria:

* Having a DSM-5 diagnosis of a psychiatric disorder
* Distressing AVH for minimally 3 months.
* Age 16 years or older

Exclusion Criteria:

* Insufficient command of the Dutch language
* Unable to provide informed consent
* Primary diagnosis of a substance use disorder, or organic brain disease (such as dementia)
* A degree of substance abuse that hinders treatment adherence
* Auditory verbal hallucinations in a language not spoken by therapists
* Patients cannot receive CBT specifically focused at gaining empowerment over voices during the study period or 6 months prior to enrolment.