Mechanisms of change in depression and anxiety within a mind-body activity intervention for chronic pain

Background: Chronic pain is challenging and costly to treat. Depression and anxiety co-occur with chronic pain. Identifying psychosocial mechanisms contributing to emotional outcomes among chronic pain patients can inform future iterations of this intervention. Methods: We examined explanatory mechanisms of change in emotional distress following a mind-body and activity intervention among 82 participants (21 – 79 years old, 65.85% female, 80.48% White). With depression and anxiety as outcomes, we hypothesized that potential mediators would include pain catastrophizing, mindfulness, and pain resilience. We used mixed-effects modeling to assess the indirect effects of time on each outcome variable through hypothesized mediators simultaneously. Results: Improvements in depression from baseline to post-treatment were most explained by pain catastrophizing (b = -2.53, CI = [-3.82, -1.43]), followed by mindfulness (b = -1.21, CI = [-2.15, -0.46]), and pain resilience (b = -0.76, CI = [-1.54, -1.66]). Improvements in anxiety from baseline to post-treatment were most explained by pain catastrophizing(b = -2.16, CI = [-3.45, -1.08]) and mindfulness (b = -1.51, CI = [-2.60, -0.65]), but not by pain resilience, (b = -0.47, CI = [-1.26, 0.17]). Limitations: Findings are limited by the lack of a control group, relatively small sample, and two timepoints. However, findings can guide future mind-body intervention efficacy testing trials. Conclusions: Pain catastrophizing and mindfulness appear to be important intervention targets to enhance emotional functioning for chronic pain patients, and should be considered simultaneously in interventions for chronic pain.