A comprehensive study based on a dataset of more than 2,400 participants in mindfulness-based stress reduction programmes found that mindfulness meditation is not harmful in terms of psychological or physical symptoms, compared to no treatment. To the contrary, MBSR in the community appears to prevent harm.
Research on the negative effects of meditation
We recently reviewed evidence concerning negative side effects of meditation and concluded that taken together, “these studies and – to some extent also the media reports – indicate that negative, adverse or unwanted effects of meditation do occur. Moreover, they highlight that scientifically little is known about what causes such negative effects and what factors may increase their prevalence.”
Our conclusion was based on relatively sparse empirical evidence and our consideration of this evidence highlighted the paucity of research. Thus, this new study by Matthew Hirshberg and co-authors, from Richard Davidson’s group at the Center for Healthy Minds is timely and very welcome. It goes beyond the primarily anecdotal evidence published in diverse media outlets and significantly deepens the discussion on this topic.
Their study was recently published on PsyArXiv, the preprint server for psychological science. We should, thus, keep in mind that it still awaits peer review, i.e. hasn’t undergone full scrutiny by scientific experts. Nevertheless, the results are important and may be helpful in discussions on the topic.
Looking for harm in mindfulness meditation
The researchers analysed an observational dataset (2155 participants) from community-based mindfulness-based stress reduction (MBSR) classes, and from three randomised controlled studies that included 156 MBSR participants and 118 participants in waitlist control groups.
When considering potentially negative effects of MBSR, the authors defined harm as outcomes that are worse than would have been expected had no treatment taken place.
In total, 44 comparisons using 22 different estimates of harm were calculated. Considering the underlying statistics, there was a 90% likelihood to find at least one significant indicator of harm purely by chance. Despite these odds, the researchers found not a single significant indicator of harm. Quite to the contrary, in half of the comparisons significantly lower rates of harm were found than without treatment. This harm-preventing effect of MBSR – of course – reflects the well-known positive impact of MBSR in reducing psychological deficits (e.g. stress, anxiety, depression).
MBSR appears to reduce harm
These results show that mindfulness meditation is not harmful. MBSR is more likely to reduce harm (that’s why it is called stress reduction), rather than induce harm.
However, the authors acknowledge that this study only captures a small fraction of the rich universe of different meditation approaches. It does not invalidate concerns about adverse meditation effects from practices that extend beyond the relatively brief, manualised MBSR programme. In particular, they point out that their research “does not shed light on the potential for deleterious outcomes during intensive mediation practice (e.g., intensive retreat).”