Are School-Based Mindfulness Interventions Effective? a Systematic Review and Meta-Analysis

Background: Evidence suggests that students today are experiencing high levels of stress as well as other emotional and developmental challenges that may impede their ability to learn and succeed in school. As schools have struggled to find ways to support students’ overall well-being and improve achievement, one approach gaining widespread support by schools, practitioners and policy makers to address multiple and varied outcomes is mindfulness-based interventions (MBIs). While the evidence of MBI’s for adults is growing and pointing to positive effects, the effects of MBIs with children is largely unknown. The purpose of this review was to examine and synthesize evidence of MBIs implemented in school settings with primary and secondary school students on academic, behavioral, cognitive and socioemotional outcomes to inform practice and policy.

Methods: Systematic review and meta-analytic procedures were used to examine effects of school-based MBIs on academic, behavioral, and socioemotional outcomes for participants relative to non-participants. A comprehensive and systematic search was undertaken to locate published and unpublished randomized or quasi-experimental studies conducted between 1990 and 2016. Descriptive analysis was conducted to examine and describe characteristics of included studies including risk of bias. Two coders independently screened studies and extracted data from included studies. Effect sizes were calculated using the standard mean difference effect size statistic, corrected for small sample size bias (Hedges’ g). Meta-analysis, assuming random effects models using inverse variance weights, was used to quantitatively synthesize results across studies.

Results: Thirty-five studies met inclusion criteria for this review. Overall, there was a moderate to high risk of bias across the 35 studies. Meta-analytic findings indicate small, yet statistically significant effects on cognitive outcomes (k = 10; g = 0.25 (95% CI [0.06, 0.43], p = .01) and socioemotional outcomes (k = 28; g = 0.22 (95% CI [0.14, 0.30], p < .001), and small and non-significant effects on academic outcomes (k = 5; g = 0.27 (95% CI [-0.04, 0.57], p = .08.) and behavioral outcomes (k = 13; g = 0.14 (95% CI [-0.02, 0.30], p = .08). Heterogeneity was small and not statistically significant in all meta-analyses with the exception of behavioral outcomes (I² = 48%; T² = .034; Q = 22.96, p = .03).

Discussion: The effects of the MBIs included in this review were mixed across across the outcomes of interest in this review, with small positive effects observed on cognitive and socioemotional outcomes and positive, yet non-significant effects on academic and behavioral outcomes. The findings largely correspond to what we might expect given the mechanisms by which mindfulness interventions are hypothesized to work (i.e., more directly targeting cognitive and socioemotional processes). Additionally, we know little about the costs and adverse effects of school-based MBIs—the costs of implementing these programs may not be justified, and there are some indications that MBIs may have some adverse effects on youth. Given our findings, along with the risk of bias across studies, the evidence from this review urges caution in the enthusiasm for, and widespread adoption of, MBIs in schools.