Facilitating relaxation and stress reduction in healthy participants through a virtual reality intervention: Study protocol for a randomized controlled trial

* Background: Repeated or chronic stress is considered a major source of disease, in terms of both somatic and mental illness. The prevention of stress-related disease by interventions for relaxation has thus increasing societal relevance. In this randomized controlled trial, we will compare a newly developed virtual reality (VR) environment for relaxation to an active control group applying a freely chosen relaxation method. To directly test if our VR environment supports relaxation in a situation of acute stress, a standardized stress induction protocol will precede the relaxation phase.* Methods: One hundred healthy participants will be recruited from the University of Siegen and randomly assigned to the VR or the free relaxation group. The multi-sensory VR includes visual, acoustic, and haptic features to induce a strong feeling of presence. The laboratory testing will comprise a baseline measurement, a stress induction, the relaxation intervention, and a recovery measurement. The primary outcomes are self-reported stress and relaxation measured with a visual analogue scale (VAS) at pre and post baseline, at start, middle, and end of the stress induction, at pre and post relaxation, at pre and post recovery, and in the evening of testing. Secondary outcomes are the physiological parameters recorded during the four experimental phases as well as, state mood, and state rumination assessed at four time points (pre and post stress, post relaxation and in the evening of testing). Finally, post event processing will be assessed after relaxation and in the evening of testing. General linear models with repeated measures will be performed to test for statistical effects of group, time and group x time interaction.* Discussion: The newly developed, multi-sensory VR offers an intervention for relaxation without prior training. Its immersive character might increase efficacy compared to other relaxation methods, especially in situations of acute stress. Future directions could be the development of a mobile version of the VR to enhance accessibility for users. To achieve a transfer of training effects to real life, VR components should successively be eliminated until relaxation is practiced without guidance by the VR.* Trial registration: Registered with ISRCTN registry (Trial ID: ISRCTN11162338) on January 22nd 2021.