Hannes Simon Kettner ^1,2* David Glowacki ^3,4 Justin Wall ^3,4,5 Robin Carhart-Harris ^2,6 Leor Roseman ⁷ Joseph Hardy ^3,5*

• ¹ Centre for Psychedelic Research, Imperial College London, London, United Kingdom
• ² Psychedelics Division, Neuroscape, Department of Neurology, Physiology and Psychiatry, University of California San Francisco, San Francisco, United States
• ³ aNUma, Inc., San Rafael, CA, United States
• ⁴ Intangible Realities Laboratory, Centro Singular de Investigación en Tecnoloxías Intelixentes da USC, Universidade de Santiago de Compostela, Santiago de Compostela, Spain
• ⁵ Numadelic Labs, El Cerrito, CA, United States
• ⁶ Departments of Physiology and Psychiatry, University of California San Francisco, San Francisco, CA, United States
• ⁷ Department of Psychology, University of Exeter, Exeter, United Kingdom

Introduction. Being diagnosed with a life-threatening illness (LTI) is often accompanied by feelings of fear, uncertainty, and loneliness that can severely impact mental health. Relatively few interventions are available to address the existential concerns of individuals facing LTI, while treatment of the underlying physical ailment typically remains the priority of the healthcare system. Research has shown that psychedelic-assisted psychotherapy (PAT) holds promise for supporting mental health in people with LTIs. However, PAT’s potential in this population remains curtailed by several limitations, including regulatory and accessibility issues. Novel approaches that could provide some of the benefits of psychedelic experiences, while avoiding associated challenges, would therefore be highly desirable for supporting the mental well-being of people with LTIs. Among such interventions, VR-based experiences have been suggested as a promising candidate. We here evaluate a program that includes weakly representational, multi-user VR experiences based on a design aesthetic previously described as “numadelic”, which has been demonstrated to elicit self-transcendent experiences comparable to psychedelics. Methods. A prospective cohort study design was used to assess the effects of “Clear Light” (CL) a group-based, 6-session multimedia program that included VR experiences, video calls, and text chats spanning 3 weeks. Participants were individuals suffering from LTIs that self-selected to participate in the CL program. A total of N=15 participants were evaluated based on assessments one week before and after the program, using self-report measures of anxiety, depression, well-being, and secondary psychological outcomes. Results. The intervention was well-tolerated among participants. Significant improvements with moderate effect sizes were observed on self-reported measures of anxiety, depression, and well-being. Secondary measures assessing demoralization, connectedness, and spiritual well-being also showed significant improvements. Discussion. This observational study demonstrated the feasibility and potential benefits of a group-based VR program that can be delivered at-home to people suffering from LTIs. While conclusions are presently limited by the lack of randomization or a comparison group, our findings strongly suggest further research is warranted, including randomized controlled trials.