Investigator Meditation Practice Predicts Efficacy of Child/Adolescent Mindfulness-Based Interventions: A Meta-Analysis.

INTRODUCTION Mindfulness has been shown to benefit children and adolescents. However, predictors of treatment effects of mindfulness-based interventions (MBIs) are less well-known. OBJECTIVE Test the treatment effect of MBIs in children/adolescents; test for moderation by meditation practice history (MPH) of the investigator(s); compare moderation by MPH to other study- and participant-level variables. METHODS Studies were identified in PubMed and Google Scholar. English-language reports of clinical trials testing an MBI in youth were included. Investigator MPH was collected via online survey distributed to the first, last, and/or corresponding authors of included studies. Data were analyzed using random-effects models. We preformed omnibus, moderator, and multiple publication bias analyses. Treatment efficacy (Hedge's g and r) was the primary outcome. Secondary analyses included tests for moderation by study- and participant-level characteristics, and investigator MPH. RESULTS Data were included from 107 studies, including 1,393 statistics and 8,510 participants. We observed a small-to-moderate significant omnibus effect size (g = 0.33, CI: 0.27-0.39). MBI effects were significantly associated with minutes investigators meditated in the past 24 hours (p=0.05) and number of times investigators meditated in the past 7 days (p<0.01), with those meditating >30 minutes (g=0.51 [0.35-0.66]) and more than 7 times (g=0.52 [0.39-0.65]), respectively, displaying the highest effect sizes. CONCLUSION These findings confirm the benefit of MBIs in youth. We provide novel evidence that greater investigator MPH is significantly associated with better treatment outcomes. The results may invite a new way of thinking about and evaluating the mental health treatment literature and may motivate similar studies in other populations or interventions.