This study was done as ancillary mechanistic sub-study overlaid on a clinical trial , researchers used EEG to test whether participation in MORE versus supportive group (SG) psychotherapy would occasion increased alpha and theta power as well as FMT coherence during a laboratory-based mindfulness meditation session. Mindfulness meditation has been shown to modulate frontal midline theta (FMT) and alpha oscillations that are linked with marked alterations in self-referential processing. Veterans are more likely to experience pain than the general population, with 29% of Veterans reporting chronic pain. Between 2010 and 2016, 25% of Veterans with chronic pain received an opioid prescription .

Further, they hypothesized that increased theta power would be associated with altered self-referential processing during the meditative state and predictive of decreased opioid dosing following treatment with MORE.

Participants treated with MORE demonstrated significantly increased alpha and theta power (with larger theta power effect sizes) as well as increased FMT coherence relative to those in the control condition—neural changes that were associated with altered self-referential processing. Before and after 8 weeks of MORE or a supportive psychotherapy control, veterans receiving LTOT (N = 62) practiced mindfulness meditation while EEG was recorded.

In conclusion, Study results suggest that mindfulness meditation practice may produce endogenous theta stimulation in the prefrontal cortex, thereby enhancing inhibitory control over opioid dose escalation behaviors. Following 8 weeks of treatment with MORE, Veterans receiving LTOT for chronic pain exhibited increased theta and alpha power, as well as enhanced FMT coherence, during a closed-eye mindfulness meditation that predicted decreases in opioid dose four months post-treatment.