Here, we developed and examined a new way of disseminating mindfulness in nature to people without meditation experience, based on the finding that mindfulness conducted in natural settings may have added benefits. We evaluated a 5-day residential programme aiming to reduce stress and improve mental health outcomes. We compared an indoor and an outdoor version of the programme to a control group in a pilot randomised controlled trial (RCT). Sixty Danish university students experiencing moderate to high levels of stress were randomised into a residential mindfulness programme indoors (n = 20), in nature (n = 22), or a control group (n = 18). Participants completed the Perceived Stress Scale and the Self-Compassion Scale (primary outcomes) along with additional secondary outcome measures at the start and end of the program and 3 months after. Stress was decreased with small to medium effect sizes post-intervention, although not statistically significant. Self-compassion increased post-intervention, but effect sizes were small and not significant. At follow-up, changes in stress were not significant, however self-compassion increased for both interventions with medium-sized effects. For the intervention groups, medium- to large-sized positive effects on trait mindfulness after a behavioural task were found post-intervention, and small- to medium-sized effects in self-reported mindfulness were seen at follow-up. Connectedness to Nature was the only outcome measure with an incremental effect in nature, exceeding the control with a medium-sized effect at follow-up. All participants in the nature arm completed the intervention, and so did 97% of the participants in all three arms. Overall, the results encourage the conduct of a larger-scale RCT, but only after adjusting some elements of the programme to better fit and take advantage of the potential benefits of the natural environment.
Keywords: meditation; nature-based mindfulness; retreat; self-compassion; stress reduction.