Virtual-reality (VR) therapy for anxiety disorders has emerged with the advent of VR technology. Its superior efficacy to waitlist and comparable efficacy to in vivo exposure therapy (Carl et al., 2019) make VR therapy a viable psychological intervention. VR therapy offers several accessibility benefits to encourage help-seeking among those who are less inclined to engage in face-to-face therapy and those with mild-to-moderate and/or sub-clinical levels of anxiety who might not reach threshold for clinical referral. This special issue aimed to understand the advantages and limits of VR therapy in improving symptoms of anxiety. Anxiety is the anticipation of real threat (Penninx et al., 2021; Hamm, 2020). Anxiety is characterized by “muscle tension and vigilance in preparation for future danger and cautious avoidance behavior” (American Psychiatric Association, 2013). Anxiety includes a cognitive element, including a fear of the worst happening, and a physiological element, such as heightened arousal, sweating and feeling faint (Creamer et al., 1995). The objectives of this special issue were to understand:

• The theoretical significance of VR therapy for clinical and sub-clinical levels of anxiety,

Research on virtual reality for anxiety disorders must be guided by theory because the “wow” factor of the technology can lead people to develop virtual environments for clinical applications acontextually. An early randomized clinical trial used virtual reality for fear of heights (Rothbaum et al., 1995) and it relied on emotional processing theory (Foa and Kozak, 1986), which suggests that exposure therapy modulates a dysfunctional fear structure and provides information that is incompatible with the fear-associated memory. In this issue, Jerath and Beveridge draw on theories of the philosophy of mind and theories of global and spatial cognition to inspire future research on how virtual reality can improve anxiety through the creation of massive virtual spaces, such as looking at a clear sky at night. The authors suggest that anxiety is characterized by vicious cycles that can be interrupted by transcendent experiences created in expansive virtual spaces, like the cosmos, using slow deep breathing and biofeedback. Advances in VR technology to create massive spaces through testable hypotheses would yield exciting possibilities to investigate the benefits of transcendent virtual experiences.

VR technology holds promise for self-guided VR therapy where the user has full control over increasing their exposure to threat in the absence of a therapist (Zainal et al., 2021; Premkumar et al.). Participants with high self-reported public-speaking anxiety increased their exposure to the modifiable virtual threats over two sessions of self-guided VR therapy (Premkumar et al.). Findings of sustained improvement in public-speaking anxiety and social anxiety 1 month after the intervention in this preliminary study suggest the long-term benefits of self-guided VR therapy. Where anxiety is brought about by chronic physical illness, such as cancer, VR therapy can construct positive virtual environments. MIND (2021) note that “spending time in green space or bringing nature into your everyday life can benefit both your mental and physical wellbeing” (Naor and Mayseless, 2021). It is within this context that Wilson and Scorsone explored the benefits of bringing people closer to nature through immersive VR therapy and inducing positive emotions and reducing pain levels. Selecting among a wide range of nature-inspired immersive audio-visual experiences to promote relaxation during treatment via chemotherapy, participants receiving intravenous chemotherapy felt more calm, relaxed, and content, as well as less tense, thereby improving adherence to treatment. This anxiety-reducing impact of VR therapy during treatment for physical condition is true of other related conditions, such as stroke rehabilitation (Standen et al., 2017).

There is a need to understand more precisely the mechanisms of anxiety reduction that can be incorporated into VR therapies. To this end, Pfaller et al. highlighted the role of social presence in evoking emotional responses during specific agent social interactions. Thus, manipulating social presence may lead to more effective interventions in improving social interaction. A further mechanism of VR therapy is to gain control over anxious thoughts through attention training. Wechsler et al. examined the effect of external-focus attention training in participants with high public-speaking anxiety. Training participants to attend to members of the audience in the virtual environment increased the time they spent looking at the virtual audience during a post-training public-speech and enhanced their positive affect. Thus, attending to a virtual core threat is a key mechanism of VR exposure therapy.

There are also physiological mechanisms that alter anxiety response. Joeng et al. examined the impact of diaphragmatic breathing (DB, increasing breathing volume and allowing more air to the body) and progressive muscle relaxation (PMR, sequentially alternating muscle tension and relaxation) exercises in a VR-based relaxation training program. Levels of tension after PMR were lower in those who trained in VR compared to a control group. DB decreased tension in the VR group, particularly when they practiced in virtual outdoor anxiety-provoking environments. DB primarily strengthens the parasympathetic response, whilst also improving sustained attention and decreasing negative affect (Ma et al., 2017). Thus, incorporating both physiological techniques as training elements to facilitate additional coping strategies, would aid VR-based anxiety exposure therapies.

Cybersickness, such as dizziness and motion-sickness, affects the engagement in and experience of VR therapy. Controlling for cybersickness in research on VR therapy is necessary and it requires a validated measure of cybersickness that segregates cybersickness from the target psychological symptoms of the intended intervention. Besides confirming the two-factor structure of the simulation-sickness questionnaire (SSQ, study 1), Bouchard et al. also revealed that anxiety during stress-exposure (the Trier Social Stress Test, study 2) was confounded by cybersickness. They found that most items (11 out of 16) of the SSQ correlated with state anxiety during stress-exposure, and these correlations were split evenly across the two factors of the SSQ. Scores on the SSQ increased after stress exposure and before immersion in a virtual environment. Thus, cybersickness may be confused with anxiety during administration of VR therapy and such symptoms need to be controlled for when examining the efficacy of VR therapy.

This special issue has revealed the potential for theoretically-meaningful innovations in VR therapy. The scope for novel VR therapies to integrate virtual wide open spaces, self-guided exposure and relaxation, whilst enhancing social presence through attention training and addressing cybersickness demonstrates the immense possibilities of virtual reality.