Background: The Gaia program is a 12-week mindfulness intervention based on cultivating body, emotional, and ecological self-awareness. It has shown to be effective in enhancing well-being as well as reducing psychological distress and internalizing problems among children and adolescents. Objective: The aim of this study is twofold: to assess the effectiveness of the program on basic human values and wellbeing, and to test the mediating effect of wellbeing dimensions in the relationship between mindfulness and human values. Methods: A total of 286 adolescent students were randomly assigned to the experimental and to the control group; each participant completed the Psychological Well-being Scale and the Portrait Values Questionnaire at baseline and at 3-months post-test. A multilevel regression model was carried out to test the effectiveness of the Gaia program on outcome measures, while a Half Longitudinal Structural Equation Mediation Model was conducted to test the mediating effects. Results: We observed significant positive effects of the Gaia Program on the overall Psychological Well-being score, as well as on its dimensions of Self-Acceptance and Personal Growth. Among basic human values, only Self-enhancement was affected. Furthermore, we found that the Gaia Program positively influenced Self-transcendence value through Personal Growth (b =.055, Monte Carlo 95% CI.005;.129). Conclusions: While Self-enhancement was the only value to benefit from the Gaia program, no significant results were found regarding the well-being dimensions that might serve as key processes in how mindfulness influences its development among adolescents.
