An international team of researchers recently published a meta-analysis of randomized controlled trials examining the efficacy of meditation-based therapies. Thirteen randomized controlled clinical trials (RCTs) were included: seven, with 270 participants, focused on children and adolescents; the other six, with 339 participants, on adults. Because only one of the RCTs was appropriately blinded, the results discussed below, although promising, must be considered preliminary.
Among children and adolescents, meta-analysis revealed a significant, medium effect size (SMD = -0.44, 95% CI -0.69 to -0.19) on ADHD symptoms for meditation therapy versus no treatment. There was virtually no heterogeneity among studies and no sign of publication bias. Improvements in inattention and hyperactivity/impulsivity had similar effect sizes. Neuropsychological measures of inhibition and attention indicated small-to-medium effect sizes, but failed to achieve statistically significance, perhaps due to the small numbers of trials and participants (159 and 179, respectively).
For adults, the significant effect size on ADHD symptoms was medium-to-large (SMD = -.66, 95% CI -1.21 to -0.11). Once again, there was little sign of publication bias. But in this case, there was great heterogeneity among the studies. Improvements in inattention and hyperactivity/impulsivity were again comparable, although they fell just short of statistical significance for the latter. Neuropsychological measures of the efficacy of medication therapy produced statistically significant medium effect sizes for inhibition (SMD = -0.54) and working memory (SMD = – 0.42), with virtually no heterogeneity or sign of publication bias.
Although these results are promising, the authors of the meta-analysis concluded, “Despite statistically significant effects on ADHD combined core symptoms, due to paucity of RCTs, heterogeneity across studies and lack of studies at low risk of bias, there is insufficient methodologically sound evidence to support meditation-based therapies for ADHD.”
Junhua Zhang, Amparo Díaz-Román, Samuele Cortese, “Meditation-based therapies for attention-deficit/hyperactivity disorder in children, adolescents and adults: a systematic review and meta-analysis,” Evidence-Based Mental Health, Published Online First: 10 July 2018. doi:10.1136/ebmental-2018-300015 (2018).