Can personalized Virtual Reality be better than Guided Imagery in enhancing the impact of Progressive Muscle Relaxation Training?: A Pilot Randomized Controlled Study on an Italian university sample (Preprint)

Background: Empirical evidence has shown that virtual reality (VR) scenarios can increase the effects of relaxation techniques, reducing anxiety by enabling people to experience emotional conditions in more vivid settings. Objective: This pilot randomized controlled study aims to investigate whether the progressive muscle relaxation technique (PMRT) associated with a personalized scenario in VR promotes psychological well-being and facilitates the recall of relaxing images more than the standard complementary intervention that involves the integration of PMRT and guided imagery (GI). Methods: On the basis of a longitudinal, between-subject design, 72 university students were randomly exposed to one of two experimental conditions: (1) standard complementary procedure (PMRT and GI exposure) and (2) experimental procedure (PMRT and personalized VR exposure). Individuals were assessed by a therapist before and after 7 training sessions based on measures investigating anxiety, depression, quality of life, coping strategies, sense of presence, engagement, and side effects related to VR exposure. Heart rate data were also collected. Results: Differences in changes between the 2 groups after the in vivo PMRT session conducted by the psychotherapist (T1) were statistically significant for state anxiety (F1,67=30.56; P<.001) and heart rate (F1,67=4.87; P=.01). Individuals in the VR group obtained lower scores both before (t67=-2.63; P=.01; Cohen d=0.91) and after (t67=-7.23; P<.001; Cohen d=2.45) the relaxation session when it was self-administered by participants (T2). A significant reduction in perceived state anxiety at T1 and T2 was observed for both groups (P<.001). After the VR experience, individuals reported feeling higher engagement in the experience than what was mentioned by participants in the GI group (F1,67=2.85; P=.03; ηp2=0.15), and they experienced the environment as more realistic (F1,67=4.38; P=.003; ηp2=0.21). No differences between groups regarding sense of presence were found (F1,67=1.99; P=.11; ηp2=0.11). Individuals exposed before to the VR scenario (T1) referred to perceiving the scenario recalled in-imagination at T2 as more realistic than what those in the GI group experienced (F1,67=3.21; P=.02; ηp2=0.12). The VR group had lower trait anxiety levels than the GI group after the relaxation session during session 7 (T2; t67=-2.43; P=.02). Conclusions: Personalized relaxing VR scenarios can contribute to improving relaxation and decreasing anxiety when integrated with PMRT as a complementary relaxation method. Trial registration: ClinicalTrials.gov NCT05478941; https://classic.clinicaltrials.gov/ct2/show/NCT05478941. International registered report identifier (irrid): RR2-10.2196/44183.