Abstract

There is a continuous increase in the number of studies showing that mindfulness training has a direct effect on reducing physical pain by regulating brain activation. However, most of the studies have confirmed the effect of pain control after intentionally inducing pain in healthy adults. Therefore, the limitation is that the results cannot be generalized to chronic pain. In order to address this limitation, this study focused on works that verified the physiological effect of the brain after mindfulness training targeting patients with chronic pain. To this end, a systematic literature review was conducted using PubMed and the Cochrane CENTRAL database. A total of four studies met the inclusion criteria, and they were additionally compared with four studies in healthy adults. The degree of pain measured using a subjective scale showed a significant reduction in pain after mindfulness training compared to that in the control group and before training for both chronic pain and acute pain. Changes in mindfulness skills by using subjective scales showed differences according to the mindfulness scales. In the chronic pain study, two studies measured the degree of mindfulness change with the Cognitive and Affective Mindfulness Scale-Revised (CAMS-R) and Kentucky Inventory of Mindfulness Skills (KIMS), and in the acute pain study, two studies were assessed using the Freiburg Minfulness Inventory (FMI). Results showed that only the study assessed by CAMS-R showed no significant change after mindfulness training. Functional magnetic resonance imaging (fMRI) showed that mindfulness training in both chronic pain and acute pain reduced the pain by activating the descending pain modulatory pathways, which is a higher-order brain function. However, brain activation related to bottom-up regulation instead of top-down regulation was found in cases with a training experience of an average of 10 years or more. This suggests that the mechanism of the brain for controlling pain may also vary depending on the level of mindfulness. Studies verifying the brain mechanism of mindfulness in pain control is still in its infancy, and more research should be conducted in the future. This study is significant as it is the first attempt to compare the brain physiological effects of mindfulness in pain management by dividing them into chronic pain and acute pain. The results of this study reaffirmed that mindfulness training in pain management can cause significant pain reduction in chronic pain and acute pain. Moreover, suggestions for future research were discussed.