Inferiority or Even Superiority of Virtual Reality Exposure Therapy in Phobias?—A Systematic Review and Quantitative Meta-Analysis on Randomized Controlled Trials Specifically Comparing the Efficacy of Virtual Reality Exposure to Gold Standard in vivo Exposure in Agoraphobia, Specific Phobia, and Social Phobia

Abstract

Background: Convincing evidence on Virtual Reality (VR) exposure for phobic anxiety disorders has been reported, however, the benchmark and golden standard for phobia treatment is in vivo exposure. For direct treatment comparisons, the control of confounding variables is essential. Therefore, the comparison of VR and in vivo exposure in studies applying an equivalent amount of exposure in both treatments is necessary.Methods: We conducted a systematic search of reports published until June 2019. Inclusion criteria covered the diagnosis of Specific Phobia, Social Phobia, or Agoraphobia, and a randomized-controlled design with an equivalent amount of exposure in VR and in vivo. We qualitatively reviewed participants' characteristics, materials, and the treatment procedures of all included studies. For quantitative synthesis, we calculated Hedges' g effect sizes for the treatment effects of VR exposure, in vivo exposure, and the comparison of VR to in vivo exposure in all studies and separately for studies on each diagnosis.Results: Nine studies (n = 371) were included, four on Specific Phobia, three on Social Phobia, and two on Agoraphobia. VR and in vivo exposure both showed large, significant effect sizes. The comparison of VR to in vivo exposure revealed a small, but non-significant effect size favoring in vivo (g = −0.20). Specifically, effect sizes for Specific Phobia (g = −0.15) and Agoraphobia (g = −0.01) were non-significant, only for Social Phobia we found a significant effect size favoring in vivo (g = −0.50). Except for Agoraphobia, effect sizes varied across studies from favoring VR to favoring in vivo exposure.Conclusions: We found no evidence that VR exposure is significantly less efficacious than in vivo exposure in Specific Phobia and Agoraphobia. The wide range of study specific effect sizes, especially in Social Phobia, indicates a high potential of VR, but also points to the need for a deeper investigation and empirical examination of relevant working mechanisms. In Social Phobia, a combination of VR exposure with cognitive interventions and the realization of virtual social interactions targeting central fears might be advantageous. Considering the advantages of VR exposure, its dissemination should be emphasized. Improvements in technology and procedures might even yield superior effects in the future.

Virtual Reality exposure therapy for public speaking anxiety in routine care: a single-subject effectiveness trial

“…More importantly, the complete control of the user's visual and auditory input makes it possible to create therapeutic experiences not available in the real world, for example being able to customize stimuli material to the user's idiosyncratic fears, or precisely manipulate the environment to target idiosyncratic catastrophic beliefs. Dozens of high-quality trials since the early 2000's support the efficacy of VR exposure therapy (VRET) for anxiety disorders (Carl et al, 2019;Fodor et al, 2018;Opriş et al, 2012), showing effect sizes similar to in-vivo exposure therapy (Wechsler et al, 2019) and that treatment effects generalize also to reduced fear of realworld equivalent phobic stimuli (Morina et al, 2015). Low rates of deterioration have also been found (Fernández-Álvarez et al, 2019).…”

Exploring the Participant-Related Determinants of Simulator Sickness in a Physical Motion Car Rollover Simulation as Measured by the Simulator Sickness Questionnaire

“…Similar conclusions on the usefulness of VRET, at least as a supplementary measure, were reached by other authors, also in the area of treating fear of driving and trauma after traffic accidents [ 79 , 80 , 81 , 82 ]. In some phobias, the effectiveness of in vivo exposure therapy seems similar to the effectiveness of VRET [ 83 , 84 ]. Therefore, it would be useful to test in the future whether physical motion simulations such as the one applied in our study—closer to an in vivo exposure than to VR—is as useful in reducing driving anxiety.…”

Better, Virtually: the Past, Present, and Future of Virtual Reality Cognitive Behavior Therapy

“…"), and then proceed to examining effectiveness ("Does the intervention work under real-world conditions?"). In the case of VR exposure therapy for anxiety disorders, more than a dozen efficacy trials conducted over 20 years have convincingly shown that this intervention is efficacious (Carl et al 2019;Fodor et al 2018;Wechsler et al 2019) and associated with low rates of deterioration (Fernández-Álvarez et al 2019). To the author's knowledge, only a single effectiveness trial of VR exposure therapy has been published to date: although it demonstrated feasibility and replicated the effect size from the preceding efficacy trial, the sample size was relatively small and for ethical and practical reasons, a single-case design was chosen instead of comparison with treatment-as-usual (Lindner et al 2020a).…”

“…This narrative review will introduce readers to VR technology and how it can be put to clinical use, and discuss the past, present, and future of VR-CBT for mental disorders. The aim is not to provide a systematic review (Freeman et al 2017) or a meta-analysis of the field (Botella et al 2017;Carl et al 2018;Wechsler et al 2019) but rather to give a historical overview and context, showing how developments in technology have fueled clinical progress. Perspectives on the future of the field will also be provided.…”