(1) Background: Virtual reality (VR) has been investigated in a variety of psychiatric disorders, including addictive disorders (ADs); (2) Objective: This systematic review evaluates the current evidence of immersive VR (using head-mounted displays) in the clinical assessment and treatment of ADs; (3) Method: PubMed and PsycINFO were queried for publications up to November 2020; (4) Results: We screened 4519 titles, 114 abstracts and 85 full-texts, and analyzed 36 articles regarding the clinical assessment (i.e., diagnostic and prognostic value; n = 19) and treatment (i.e., interventions; n = 17) of ADs. Though most VR assessment studies (n = 15/19) showed associations between VR-induced cue-reactivity and clinical parameters, only two studies specified diagnostic value. VR treatment studies based on exposure therapy showed no or negative effects. However, other VR interventions like embodied and aversive learning paradigms demonstrated positive findings. The overall study quality was rather poor; (5) Conclusion: Though VR in ADs provides ecologically valid environments to induce cue-reactivity and provide new treatment paradigms, the added clinical value in assessment and therapy remains to be elucidated before VR can be applied in clinical care. Therefore, future work should investigate VR efficacy in randomized clinical trials using well-defined clinical endpoints.

Tobacco smoking is substantially more prevalent in vulnerable groups, such as people with intellectual disability, psychiatric disorders, or low socioeconomic status. Though smoking cessation programs for the general population are available, accessible and inclusive approaches are lacking. An encouraging new approach toward more practice-oriented and tailorable smoking cessation is virtual reality. Research indicates that virtual environments (VEs) with tobacco-related cues can elicit cue-reactivity (e.g. craving and physiological responses) and provide various new options to integrate treatment approaches. Yet, the potential to elicit cue-reactivity and the practicability of cue-reactivity measures have not been studied in vulnerable groups. This explorative study aggregated the data of twenty-three vulnerable individuals, who present themselves in three clinical settings, to validate the VEs, assess the practicability of several cue-reactivity measures (i.e. selfreport questionnaires, psychophysiological data), and investigate the initial acceptance toward a prototype VE with tobacco-related cues. The results confirm the potential of the VE to elicit tobacco craving compared to baseline scores and craving in a neutral VE, as measured using one-dimensional (VAS) and multi-dimensional scales (QSU-Brief). Furthermore, the participants reported a good initial acceptance toward the VE as a potential treatment for smoking cessation. However, measuring psychophysiological responses in the clinical setting proved to be unfeasible in this research. Future studies should investigate the versatile possibilities of VEs to assess and treat vulnerable groups with tobacco dependence.

Background Immersive virtual reality (IVR) has been investigated as a tool for treating psychiatric conditions. In particular, the practical nature of IVR, by offering a doing instead of talking approach, could support people who do not benefit from existing treatments. Hence, people with mild to borderline intellectual disability (MBID; IQ=50-85) might profit particularly from IVR therapies, for instance, to circumvent issues in understanding relevant concepts and interrelations. In this context, immersing the user into a virtual body (ie, avatar) appears promising for enhancing learning (eg, by changing perspectives) and usability (eg, natural interactions). However, design requirements, immersion procedures, and proof of concept of such embodiment illusion (ie, substituting the real body with a virtual one) have not been explored in this group. Objective Our study aimed to establish design guidelines for IVR embodiment illusions in people with MBID. We explored 3 factors to induce the illusion, by testing the avatar’s appearance, locomotion using IVR controllers, and virtual object manipulation. Furthermore, we report on the feasibility to induce the embodiment illusion and provide procedural guidance. Methods We conducted a user-centered study with 29 end users in care facilities, to investigate the avatar’s appearance, controller-based locomotion (ie, teleport, joystick, or hybrid), and object manipulation. Overall, 3 iterations were conducted using semistructured interviews to explore design factors to induce embodiment illusions in our group. To further understand the influence of interactions on the illusion, we measured the sense of embodiment (SoE) during 5 interaction tasks. Results IVR embodiment illusions can be induced in adults with MBID. To induce the illusion, having a high degree of control over the body outweighed avatar customization, despite the participants’ desire to replicate their own body image. Similarly, the highest SoE was measured during object manipulation tasks, which required a combination of (virtual) locomotion and object manipulation behavior. Notably, interactions that are implausible (eg, teleport and occlusions when grabbing) showed a negative influence on SoE. In contrast, implementing artificial interaction aids into the IVR avatar’s hands (ie, for user interfaces) did not diminish the illusion, presuming that the control was unimpaired. Nonetheless, embodiment illusions showed a tedious and complex need for (control) habituation (eg, motion sickness), possibly hindering uptake in practice. Conclusions Balancing the embodiment immersion by focusing on interaction habituation (eg, controller-based locomotion) and lowering customization effort seems crucial to achieve both high SoE and usability for people with MBID. Hence, future studies should investigate the requirements for natural IVR avatar interactions by using multisensory integrations for the virtual body (eg, animations, physics-based collision, and touch) and other interaction techniques (eg, hand tracking and redirected walking). In addition, procedures and use for learning should be explored for tailored mental health therapies in people with MBID.