Mindfulness and pain: new research review hints at unique mechanism for pain relief

Introduction

Even though the effectiveness of mindfulness to reduce pain has been proven in numerous empirical studies its efficacy still remain unclear. Meaning that the effectiveness of mindfulness could be due to some other variable than the specific technique. Potential placebo responses or regression toward the mean could dilute the validity of research findings. Zeidan et al. (2012) writes that many of the studies done on mindfulness meditation are either cross-sectional or case-control designs. As such they are prone to biased conclusions due to selection bias.

Effectiveness and efficacy… what’s the mechanism?

Mindfulness has been found to attenuate pain through enhanced cognitive and emotional control, as well as altering the contextual evaluation of sensory events. In their article Zeidan et al. operationalize meditation in two overall categories. 1) Focused attention (FA) which includes techniques like focusing on your breath. And 2) Open monitoring (OM), sometimes called open awareness, which consist of techniques emphasizing non-evaluation of any sensory, emotional or cognitive events.

Differences between focused attention and open monitoring for pain relief?

It’s been hypothesized by researchers that different neural processes underlie the different forms of mindfulness meditation. And it does seem like a valid hypothesis that FA and OM practices would influence pain in different ways. Zeidan et al (2010) conclude that OM meditation seem more suited to analgesia than FA after extensive meditation training (~2000 hours of practice). However, they continue with stating that studies suggest that combining FA and OM practices might be able to help reduce pain even after brief mediation training.

Potential unique mechanism for pain relief?

Based on the studies review by the researchers they conclude that the findings suggest that mindfulness do operate by unique mechanisms. Specifically they write that:

“… placebo analgesia is typically preceded by greater activation of DLPFC [dorsolateral prefrontal cortex] during anticipation of pain, an effect that predicts reductions in pain perception and activity in pain-related brain regions. Mindfulness, on the other hand, does not appear to involve DLPFC activation.”

Moreover they write that placebo effects might work through top-down modulatory control, whereas mindfulness “seems to reduce the influence of the expectancy of pain, possibly through decreased elaboration … of nociceptive information”.

Quality of the evidence

There seem to be some evidence in this research article that mindfulness alter the contextual evaluation of pain, and that it changed over time and with meditation experience. However, I would say that this is pretty weak evidence and that it should be seen as a basis for future theorizing.

This research article isn’t a systematic review, hence it doesn’t give any information on studies exclusion or inclusion criteria, nor is there any information about how they searched for relevant articles. This makes it impossible for the reader to gage if there’s likely to be any selection bias in the included studies. Moreover there’s no discussion about the included studies’ methodological quality.

I’d rather see researchers do well implemented meta-analyses than reviews, contingent upon that they follow the guidelines in Cochrane Handbook for Systematic Reviews of Interventions.

But as a straightforward summary of some mindfulness research I’d still recommend readers to look at the review article by Zeidal et al., it gives a good explanation of current research question regarding mindfulness meditation.

Zeidan F, Grant JA, Brown CA, McHaffie JG, & Coghill RC (2012). Mindfulness Meditation-Related Pain Relief: Evidence for Unique Brain Mechanisms in the Regulation of Pain. Neuroscience letters PMID: 22487846