Condition category
Mental and Behavioural Disorders
Date applied
Date assigned
Last edited
Retrospectively registered
Overall trial status
Recruitment status
No longer recruiting
Publication status

Plain English Summary

Background and study aims
Paranoia is a mental condition where a person falsely believes that they are being persecuted by others and is deeply suspicious and mistrustful of those around them. Many paranoid patients live restricted lives; they find relationships difficult due to being so suspicious and unfriendly, suffer from social anxiety and tend to avoid all kinds of social occasions. Here, we want to see whether virtual reality technology helps to make paranoid patients feel more able to go outside and enjoy social occasions.

Who can participate?
All patients that experience fear and avoid going outside or travelling by public transportation, etc.

What does the study involve?
The patients are randomly allocated into one of two groups. Those in group 1 have up to 16 sessions of virtual reality exposure therapy over a 3 month period. Those in group 2 are placed on a waiting list for 6 months, after which they also receive the treatment. The amount of social participation (time spent with other people, including family, friends, colleagues and strangers) and feelings of paranoia experienced in social situations is measured. All participants are assessed at the start of the treatment, at the end of the treatment and 3 months after the treatment has ended.

What are the possible benefits and risks of participating?
There are no known serious risks. Some people feel sick (cyber illness) during the virtual reality exposure.

Where is the study run from?
VU University, Amsterdam (Netherlands) and the Parnassia Psychiatric Institute in the Hague (Netherlands)

When is study starting and how long is it expected to run for?
April 2014 to December 2015

Who is funding the study?
The NutsOhra Foundation (Netherlands)

Who is the main contact?
Professor Mark van der Gaag

Trial website

Contact information



Primary contact

Prof Mark van der Gaag


Contact details

van der Boechorststraat 1
1081 BT
+31 (0) 64 578 04 63

Additional identifiers

EudraCT number number

Protocol/serial number


Study information

Scientific title

The effect of Virtual Reality Exposure Therapy (VRET) on social participation in people with a psychotic disorder: a multi-site randomized controlled trial



Study hypothesis

Virtual Reality Exposure Therapy will improve real life social participation in patients with a psychotic disorder experiencing paranoia and/or social anxiety symptoms.

Ethics approval

Medical Ethical Committee of VU Medical Center; 06/03/2014; NL45965.029.13 / 2014.015

Study design

Randomised controlled trial

Primary study design


Secondary study design

Randomised controlled trial

Trial setting


Trial type


Patient information sheet

Not available in web format, please use the contact details below to request a patient information sheet


Psychotic disorders with continuing social withdrawal


In both arms treatment as usual will be provided for the psychotic disorder for which the person sought help. In the first experimental arm there will be a maximum of 16 sessions (over three months) of Virtual Reality Exposure Treatment with a trained CBT therapist aimed at improving social participation. Treatment duration is three months, patients will be followed-up at 3 months. The second arm entails a waiting list for a period of six month, after which these participants will also get the VRET treatment.

Intervention type



Not Applicable

Drug names

Primary outcome measure

1. Experience Sampling Method (ESM) on social participation.
2. Objective social participation is expressed as the amount of time spend with other people and the type of company (for example family, friends, colleagues or strangers).
3. Subjective social participation is expressed as momentary paranoia, perceived social threat and event stress as experienced in social situations.

All measures are measured at baseline, at end of treatment at 3 months, and at follow-up at 6 months.

Secondary outcome measures

1. Depression (BDI-II)
2. Stigmatisation and schemata (ISMI, BCSS)
3. Paranoia (GPTS)
4. Social interaction anxiety (SIAS)
5. Cognitive biases (DACOBS)
6. Safety behavior (Safety Behavior Questionnaire – persecutory delusions)
7. Quality of life and cost-effectiveness (MANSA,TIC-P)
8. Presence and cyber sickness (SSQ, IPQ), measured at month 1 and at month 2 during treatment.
9. Psychosis (Positive and Negative symptom scales)
10. Social functioning (Social and Occupational Functioning Assessment Scales)

Overall trial start date


Overall trial end date


Reason abandoned (if study stopped)


Participant inclusion criteria

1. Aged 18 to 65 years, either sex
2. Fullfilling diagnostic criteria for a psychotic disorder
3. Experiencing at least mild paranoia and/or social anxiety as measured with the Green et al. Paranoid Thought Scales (GPTS) and Social Interaction Anxiety Scale (SIAS)

Participant type


Age group




Target number of participants


Total final enrolment


Participant exclusion criteria

1. IQ under 70
2. Insufficient command of the Dutch language
3. Epilepsy

Recruitment start date


Recruitment end date



Countries of recruitment


Trial participating centre

van der Boechorststraat 1
1081 BT

Sponsor information


NutsOhra Foundation (Fonds NutsOhra) (Netherlands)

Sponsor details

Amstelplein 6
1096 BC
+31 (0)20 594 96 90

Sponsor type




Funder type


Funder name

Fonds NutsOhra (Netherlands)

Alternative name(s)

NutsOhra Fund

Funding Body Type


Funding Body Subtype


Results and Publications

Publication and dissemination plan

Not provided at time of registration

Intention to publish date

Participant level data

Not provided at time of registration

Basic results (scientific)

Publication list

2016 protocol in
2018 main results in (added 18/02/2019)
2018 cybersickness results in (added 18/02/2019)
2020 cost-effectiveness results in (added 06/05/2020)

Publication citations

Additional files

Editorial Notes

06/05/2020: Publication reference and total final enrolment added. 18/02/2019: Publication references added. 15/01/2016: Publication reference added.