Dunning DL, Griffiths K, Kuyken W, et al. J Child Psychol Psychiatry. First published 22 October 2018. https://doi.org/10.1111/jcpp.12980

As the evidence for mindfulness-based therapies increases, this review of 33 studies conducted before October 2017 demonstrates that these interventions can improve measures of mindfulness, anxiety and depression with small effect sizes (i.e. a positive, but modest effect).

https://onlinelibrary.wiley.com/doi/10.1111/jcpp.12980