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

The Psychotic Symptoms Rating Scales (PSYRATS) is a semi-structured interview to assess characteristics of hallucinations and delusions. The auditory hallucinations subscale (AHS), which is used as the primary outcome, has 11 items.

The Psychotic Symptoms Rating Scales (PSYRATS) is a semi-structured interview to assess characteristics of hallucinations and delusions. The auditory hallucinations subscale (AHS) has 11 items.The delusions subscale (DS) has six items.

The BAVQ-R has 54 items, measured on a four-point scale: "disagree" (0), "unsure" (1), "slightly agree" (2), "strongly agree"(3).

The SCRS has 11 items measuring characteristics of the participants as compared to their voices on a 10-point likert scale ranging from 1-10.

The VIS has 24 items measured on a 10-point likert scale ranging from 1 (totally disagree) to 10 (totally agree).

Section A of the VAAS has 12 items and section B 27. Items are rated on a 5-point scale: strongly disagree, disagree, unsure or neutral, or strongly agree.

The IDS-SR is a 30-item questionnaire. Each item has four statements that reflect various degrees of symptom severity, scored on a four-point scale from 0 to 3.

The R-GPTS part A consists of 8 items, and B of 10 items. Items are rated on a 5-point scale ranging from 0 (not at all) to 4 (totally).

The SERS has 20 items which are rated on a 7-point likert scale from 1 (strongly disagree) -7 (strongly agree).

The TiC-P is a self-report questionnaire that consists of two parts. The first part includes 38 structured questions, starting with yes/no questions and followed by a question on the volume of medical consumption.

The TiC-P is a self-report questionnaire that consists of two parts. The second part deals with 12 questions about work to collect data on productivity losses due to health problems.

The SDS is a brief, 5-item self-report tool that assesses functional impairment in work/school, social life, and family life on a scale from 0-10, and assess how many days someone missed work/school/responsibilities and how many days someone was unproductive.

The first 25 items of this questionnaires are based on five dimensions: mobility, self-care, usual activities, pain/discomfort, and anxiety/depression. The patient is asked to indicate their health status by choosing the most appropriate level: no problems, slight problems, moderate problems, severe problems, and extreme problems. The last question indicates their current health status on a scale from 0 to 100.

The MHCS has 16 items that are measured on a 6-point likert scale ranging from totally not confidant

ESM of auditory verbal hallucinations and mental states measured in the flow of daily life. ESM is a structured diary method for reporting momentary experiences 18. Individuals complete short questionnaires on their mobile device, by pressing a link in a text message. Participants will complete ESM 5x daily for 7 days, completion takes ±1 minute. Participants have to complete the questionnaire within 30 minutes after the text message notification, the interval between measurements is 3 hours.

21 items on traumatic events, whether they happened, more than once and at which age.

10 items to screen trauma which can be answered with yes or no.

Use of prescribed medication in the past 3 months, type of medication, were the medication is for, how often it was used and what amount (in milligram)

Use of substances, number of glasses of alcohol in the past month. Use of softdrugs and harddrugs in the past 3 months, type of drugs, how often the drugs were used, how much was used each time.

Frequency of use of 21 types of psychological interventions and training in the past 30 days. There is also an option 'other', where specific other interventions and the frequency can be noted down.

The WAV has 36 items for the participant and 36 items for the therapist. Items are rated on a 5-point scale ranging from ''never'' to ''always''

The IPQ has 14 items rated on 7-point likert scale ranging from fully disagree to fully agree.

Experience of fit of the voice and avatar to the actual voice (two single items on a scale from 1-100).

Frequency and duration of use of the session recordings by the participant, duration, protocol deviations

After the VR-VOICES intervention, in-depth interviews will be performed to collect the experiences of patients with VR-VOICES. This will be done in a subsample of participants (n=20)