Mindfulness-based programmes reduce psychological distress (anxiety and depression) in community adults who volunteer to participate, with a small to moderate effect size. The analysis of 13 randomized controlled trials with 2,371 participants from 8 countries found a standardized mean difference of -0.32, with high confidence in the result. The effect was not clearly influenced by participants' baseline distress level, gender, age, education, or dispositional mindfulness. More research is needed to understand why outcomes vary between individuals.
This paper describes a process of public involvement in a meta-analysis that combines both aggregate and individual participant data to examine mindfulness-based programs for mental health promotion. The involvement includes contributions from people with lived experience and members of the public in shaping the research questions, interpreting findings, and disseminating results. The work highlights how such collaboration can enhance the relevance and applicability of evidence synthesis in mental health.