A critical role of affective content in the analgesic effect of virtual reality: a cross-sectional within-subject...

The dual challenges of the opioid crisis and the global burden of chronic pain underscore the need for safe, non-pharmacological alternatives. Virtual reality (VR) is a promising digital therapeutic for pain, yet its mechanisms remain unclear. This study aimed to disentangle the roles of immersion and emotional engagement in VR-induced analgesia in individuals with temporomandibular disorders (TMD).

In a counterbalanced within-subject design, 62 adults with TMD (21 males, 41 females; mean age 34.7 years [19-55]; 57 (91.9%) non-Hispanic or Latino, 30 (48.4%) White) were exposed to seven conditions: three immersive VR environments (ocean, opera, pink noise), matched non-immersive (2D) versions, and a 2-back working memory task. Heat pain tolerance was assessed using thermal stimulation. Participants rated pain intensity, pain unpleasantness, mood, anxiety, and enjoyment. Skin conductance response (SCR) indexed autonomic arousal. Multilevel mediation models tested the underlying psychological mechanisms.

VR Ocean significantly increased heat pain tolerance (Cohen's d = 1.60), reduced pain intensity and unpleasantness, improved mood, and reduced situational anxiety relative to all other conditions (all p < 0.05). It was also rated as the most enjoyable experience (p < 0.01). Mediation analyses indicated mood (ab = -5.15) and enjoyment (ab = -6.12) significantly mediated VR Ocean's effect on pain intensity, whereas anxiety did not. No mediators explained changes in pain tolerance. SCR did not differ between VR and 2D conditions.

VR-based analgesia relies not only on immersion but also on affectively rewarding contents. Digital therapeutics that enhance positive mood and enjoyment may be especially effective for chronic pain management.

This study was supported by the National Institutes of Health and the University of Maryland.