A randomized controlled trial exploring dose-response effects of mindfulness meditation practice on wellbeing

Background/Objectives: Psychological benefits have been demonstrated across a variety of different meditation offerings. There remains, however, limited evidence clarifying how different ‘doses’ of meditation relate to benefits, highlighting fundamental limitations for clinical best practice. The present study aimed to examine dose–response effects across a range of daily mindfulness meditation durations in a well-powered randomized controlled experiment, while also investigating whether actual practice behaviour predicts improved outcomes, independent of assigned dose.Method: A total of 716 meditation-naïve, healthy adults were randomized to one of four daily mindfulness practice conditions (4-, 10-, 20-, or 30-minutes) over a 28-day online intervention. The primary outcome was wellbeing, and secondary outcomes included mindfulness-related constructs and mental health symptoms. Primary analyses used a constrained longitudinal design within an intention-to-treat approach to test for differences between assigned dose groups. Secondary per-protocol analyses were conducted to reduce effects of nonadherence. Exploratory analyses examined five measures of practice dose, alongside motivation and expectancy variables, as predictors of outcomes.Results: Significant improvements were observed across all outcomes and arms from baseline to post-intervention (|SMD| = 0.29–0.56, FDR-adjusted p < .05). We found no evidence of a dose–response effect based on assigned practice dose in either intention-to-treat or per-protocol analyses for any outcome (all p’s > .05). While 70.9% of those in the 10-minute group completed 2/3 of sessions, only 65.3% and 48.5% of participants did the same in the 20- and 30-minute groups, respectively. In exploratory analyses, practice engagement was significantly related to 8/10 outcomes ([β] = 0.05-0.14), while goal confidence was significantly related to 9/10 outcomes ([β] = 0.08-0.21), and time was significantly related to changes on all outcomes ([β] = 0.26-0.54; FDR-adjusted p < .05). Conclusions: These findings suggest that within the first 30 days of practice among non-clinical, beginner populations there is no evidence that longer doses (up to 30 min) are more beneficial than shorter doses (down to 5 min) of daily meditation, while practice engagement and confidence in the efficacy of meditation may impact effects.