Adding mindfulness to treatment as usual: A meta-analysis

Mindfulness-based interventions (MBI) are receiving increasing attention in the treatment of mental illness, and there is good support for their effectiveness as a stand-alone treatment across a range of disorders. It is possible that MBI would also be useful as an addition to standard treatment protocols. To assess this possibility, the present investigation involved a meta-analytical review of studies in which mindfulness techniques were added to treatment as usual to assess the incremental effect of mindfulness. A systematic review was conducted of relevant databases. Studies were included in the meta-analysis if they met the following criteria: (a) mindfulness techniques or mindfulness-based interventions were employed in conjunction with treatment as usual and compared to treatment as usual alone; (b) patients in the sample were assigned a DSM-IV diagnosis or exhibited a specific symptom; and (c) the sample included individuals 18 years of age or older. Only studies using an experimental randomized controlled design were included. Fourteen eligible studies were found with an effective sample size of 695 participants. Effect sizes were calculated overall, and for subgroups (diagnosis subgroups, mean age, type of MBI) separately. Meta-analysis of between-group effects yielded an overall Cohen’s d effect size of 0.61. Adding MBIs to treatment as usual appears to yield substantial incremental improvement when used with a variety of symptoms and disorders