Abstract
Forest bathing ("Shinrin-yoku"), traditionally practiced in Japan, has shown positive effects on stress perception and psychological wellbeing in highly sensitive persons (HSP), but it is unclear whether a simulation can produce the same effects. Forty-nine HSP underwent in randomized order a 40-min exposure to both an authentic forest environment and a 360° video-based virtual forest simulation using a head-mounted display, complemented by natural forest sounds and essential spruce oil diffusion. Quantitatively, wellbeing and stress reduction measured with the Change in Subjective Self-Perception as pre-specified primary outcome (CSP-14; Cohen's d: 0.931; p < 0.001) and secondary outcome state anxiety (STAI-S: Cohen's d: 1.5 vs. 0.275; p < 0.001) improved significantly more in the real forest. The forest condition also yielded greater reductions in heart rate (-7.94 vs.-3.47 bpm; Cohen's d: 0.335; p = 0.026) and superior improvements on Basel Well-Being Subscales vitality, intrapsychic balance, and vigilance (Cohen's d: 0.751, 0.466, 0.629; all p < 0.001). Furthermore, we analyzed qualitative interviews which revealed that authentic multisensory experiences in the forest significantly enhanced relaxation, reduced stress, and promoted emotional security compared to the simulation. Although the virtual environment provided temporary calming effects and facilitated reflection, technical limitations, such as visual blurring, repetitive audiovisual loops, and limited sensory diversity, considerably impaired the immersive experience. Particularly for HSP, authentic natural environments seemed to be important in our setting in achieving deeper and more sustainable psychological benefits considering the existing limitations of video-based virtual forest simulation. This study emphasizes the important value of real forest interactions in promoting psychological wellbeing and effective stress management. CLINICAL TRIAL REGISTRATION: https://drks.de/search/de/trial/DRKS00025421, identifier: DRKS00025421.