Understanding pain treatment mechanisms: a new direction in outcomes research

An in-Depth Exploration of Consumer and Consumer Representative Views on Chronic Pain Management in Australia: A Key Informant Interview Study

Chronic pain affects millions of Australians. Despite guidelines recommending non-pharmacological approaches as the first line treatment, opioid medications remain among the most common treatments. This study interviewed consumers and consumer representatives (i.e., representatives of peak pain advocacy organizations in Australia) to gain first-hand perspectives on chronic pain treatment in Australia. Individual semi-structured Key Informant Interviews (KIIs) with three consumers and three representatives were undertaken. Interviews were transcribed, and thematic analysis applied. Results showed that consumers and consumer representatives identified critical treatment access barriers. Another shared theme related to overarching principles of care, with sub-themes pertaining to the need for an interdisciplinary approach and pain education. A further shared theme focused on typical medical interventions, with one shared subtheme regarding the benefits and drawbacks of pain medications. Both groups highlighted the importance of a biopsychosocial approach with consideration of mental health, particularly related to perceived stigma and comorbidities. These findings highlight that chronic pain remains both undertreated and inadequately treated in Australia. There is a critical need to use novel approaches to overcome access barriers and stigma, and to advance precision medicine to match patients to the treatment most likely to be of benefit as early as possible in their journey.

Outcome Expectancies, Effects, and Mechanisms of Brief Training in Mindfulness Meditation vs. Loving-Kindness Meditation vs a Control Condition for Pain Management: A Randomized Pilot Study

This study investigated the analgesic effects of a single session of mindfulness meditation (MM) and loving-kindness meditation (LKM) relative to a control. A total of 100 adults with chronic or current problematic pain completed a survey and were randomized to a 20-minute MM, LKM, or audiobook control. Co-primary outcomes of pain intensity and unpleasantness and mediators of mindfulness and self-compassion were assessed pre- and posttraining. Expectancies were assessed pretraining. Pain type (chronic vs current problematic) was a covariate. Relative to the control, higher expectancies were reported for MM and LKM (P < .001). MM (d = 0.41, P = .032) and LKM (d = 0.38, P = .027) had medium effects on pain intensity, with greater decreases than control (d = 0.05, P = .768). All conditions had small effects on unpleasantness. Mindful observing increased more within MM (d = 0.52, P = .022) and the control (d = 0.50, P = .011) than LKM (d = 0.12, P = .50); self-compassion increased more in LKM (d = 0.36, P = .042) than MM (d = 0.27, P = .201) and the control (d = 0.22, P = .249). The mediation models were nonsignificant. Pain type was a nonsignificant covariate. Overall, MM and LKM were associated with positive expectancies and small-medium pain intensity reductions, which did not differ by pain type. Although MM and LKM were associated with changes in theorized mediators, these changes did not underlie improvement.

Effects of Savoring Meditation on Positive Emotions and Pain-Related Brain Function: A Mechanistic Randomized Controlled Trial in People With Rheumatoid Arthritis

Positive emotions are a promising target for intervention in chronic pain, but mixed findings across trials to date suggest that existing interventions may not be optimized to efficiently engage the target. The aim of the current pilot mechanistic randomized controlled trial was to test the effects of a positive emotion-enhancing intervention called Savoring Meditation on pain-related neural and behavioral targets in patients with rheumatoid arthritis. Participants included 44 patients with a physician-confirmed diagnosis of rheumatoid arthritis (n = 29 included in functional magnetic resonance imaging (fMRI) analyses), who were randomized to either Savoring Meditation or a Slow Breathing control. Both meditation interventions were brief (four 20-minute sessions). Self-report measures were collected pre-and post-intervention. An fMRI task was conducted at post-intervention, during which participants practiced the meditation technique on which they had been trained while exposed to non-painful and painful thermal stimuli. Savoring significantly reduced experimental pain intensity ratings relative to rest (P < .001). Savoring also increased cerebral blood flow in the ventromedial prefrontal cortex and increased connectivity between the ventromedial prefrontal cortex and caudate during noxious thermal stimulation relative to Slow Breathing (z = 2.3 voxelwise, false discovery rate cluster corrected P = .05). Participants in the Savoring condition also reported significantly increased positive emotions (ps < .05) and reduced anhedonic symptoms (P < .01) from pre- to post-intervention. These findings suggest that Savoring recruits reward-enhancing corticostriatal circuits in the face of pain, and future work should extend these findings to evaluate if these mechanisms of Savoring are associated with improved clinical pain outcomes in diverse patient populations. PERSPECTIVE: Savoring Meditation is a novel positive emotion-enhancing intervention designed for patients with chronic pain. The present findings provide preliminary evidence that Savoring Meditation is acutely analgesic, and engages neural and subjective emotional targets that are relevant to pain self-management. Future work should evaluate the clinical translation of these findings.

Effects of Savoring Meditation on Positive Emotions and Pain-Related Brain Function: A Mechanistic Randomized Controlled Trial in People With Rheumatoid Arthritis

Positive emotions are a promising target for intervention in chronic pain, but mixed findings across trials to date suggest that existing interventions may not be optimized to efficiently engage the target. The aim of the current mechanistic randomized controlled trial was to test the effects of a single skill positive emotion-enhancing intervention called Savoring Meditation on pain-related neural and behavioral targets in patients with rheumatoid arthritis (RA). Participants included 44 patients with a physician-confirmed diagnosis of RA (n=29 included in fMRI analyses), who were randomized to either Savoring Meditation or a Slow Breathing control. Both meditation interventions were brief (four 20-minute sessions). Self-report measures were collected pre- and post-intervention. An fMRI task was conducted at post-intervention, during which participants practiced the meditation technique on which they had been trained while exposed to non-painful and painful thermal stimuli. Relative to Slow Breathing, Savoring significantly reduced experimental pain intensity ratings relative to rest (p<.001), increased cerebral blood flow in the ventromedial prefrontal cortex (vmPFC) and increased connectivity between the vmPFC and caudate during noxious thermal stimulation (z=2.3 voxelwise, FDR cluster corrected p=0.05). Participants in the Savoring condition also reported significantly increased positive emotions (ps<.05) and reduced anhedonic symptoms (p<.01) from pre- to post-intervention. These findings suggest that that Savoring recruits reward-enhancing corticostriatal circuits in the face of pain, and future work should extend these findings to evaluate if these mechanisms of Savoring are associated with improved clinical pain outcomes in diverse patient populations.

Pain-Related Beliefs, Coping, and Function: An Observational Study on the Moderating Influence of Country of Origin

Chronic pain is a multidimensional experience and pain treatments targeting psychosocial factors reduce pain and improve function. These treatments often overlook the sociocultural factors that influence pain and the psychological factors associated with function in people with chronic pain. Although preliminary findings suggest that cultural background may influence pain and function via their effects on beliefs and coping, no previous study has directly tested if the country of origin moderates the associations between these psychological factors and pain and function. This study sought to address this knowledge gap. Five hundred sixty-one adults with chronic pain, born and living in the USA (n = 273) or Portugal (n = 288), completed measures of pain, function, pain-related beliefs, and coping. Between-country similarities were found in the endorsement of beliefs related to disability, pain control, and emotion, and in asking for assistance, task persistence, and coping self-statement responses. Portuguese participants reported greater endorsement of harm, medication, solicitude, and medical cure beliefs, more frequent use of relaxation and support seeking, and less frequent use of guarding, resting, and exercising/stretching. In both countries, disability and harm beliefs and guarding responses were associated with worse outcomes; pain control and task persistence were associated with better outcomes. Six country-related small effect-size moderation effects emerged, such that task persistence and guarding are stronger predictors of pain and function in adults from the USA, but pain control, disability, emotion, and medication beliefs are more important in adults from Portugal. Some modifications may be needed when adapting multidisciplinary treatments from one country to another. PERSPECTIVE: This article examines the similarities and differences in beliefs and coping endorsed by adults with chronic pain from 2 countries, and the potential moderation effects of country on the associations between these variables and pain and function. The findings suggest that some modifications may be needed when culturally customizing psychological pain treatments.

Immediate Effects of Hypnosis, Mindfulness Meditation, and Prayer on Cold Pressor Outcomes: A Four-Arm Parallel Experimental Study

Purpose

Previous research supports the usefulness of hypnosis (HYP), mindfulness meditation (MM), and prayer as pain self-management strategies in adults with chronic pain. However, their effects on acute pain have been less researched, and no previous head-to-head study compared the immediate effects of these three approaches on pain-related outcomes. This study compared the immediate effects of HYP, MM, and Christian prayer (CP) on pain intensity, pain tolerance, and stress as assessed by heart rate variability (HRV).

Participants and Methods

A total of 232 healthy adults were randomly assigned to, and completed, a single 20-minute session of MM, SH, CP, or an attention control (CN), and underwent two cycles (one pre- and one post-intervention) of Cold Pressor Arm Wrap (CPAW). Sessions were audio-delivered. Participants responded to pre- and post-intervention pain intensity measurements. Pain tolerance (sec) was assessed during the CPAW cycles. HRV was assessed at baseline, and at pre- and post-intervention CPAW cycles. The study protocol was pre-registered at the ClinicalTrials.gov registry (NCT04491630).

Results

Small within-group decreases in pain intensity and small increases in pain tolerance were found for HYP and MM from the pre- to the post-intervention. Small within-group improvements in the LH/HF ratio were also found for HYP. The exploratory between-group pairwise comparisons revealed a medium effect size effects of HYP on pain tolerance relative to the control condition. The effects of CP were positive, but small and not statistically significant. Only small to medium, though non-significant, Time × Group interaction effects were found.

Conclusion

Study results suggest that single short-term HYP and MM sessions, but not biblical-based CP, may be useful for acute pain self-management, with HYP being the slightly superior option. Future research should compare the effects of different types of prayer and examine the predictors and moderators of these pain approaches' effects on pain-related outcomes.

Predictors of Outcomes Following Interdisciplinary Acceptance and Commitment Therapy for Chronic Pain: Profiling Psychological Flexibility

Background

Growing evidence demonstrates the benefit of acceptance and commitment therapy (ACT) for people with chronic pain. However, there remain people with chronic pain who do not benefit from ACT, and predicting treatment response is difficult.

Aims

This aim of this study was to investigate if baseline psychological flexibility (PF) profiles predict responses to an ACT‐based pain management programme.

Methods

Data from 415 participants attending an interdisciplinary pain management programme were included. Participants completed measures of PF processes and outcomes pre‐ and post‐treatment. Latent profile analysis was used to identify subgroups of participants based on their baseline PF scores. ANOVAs were conducted to compare subgroups of participants on outcome variables at baseline, and changes from pre‐ to post‐treatment.

Results

Three subgroups of participants were identified: (a) low PF, (b) low openness and (c) high awareness and action. The three subgroups significantly differed on all outcome measures at pre‐treatment, supporting the clinical relevance of these PF profiles. However, participants with different baseline PF profiles did not appear to differ in terms of changes in outcome variables.

Conclusions

People with chronic pain demonstrate different PF profiles, but appear to respond to ACT similarly regardless of these profiles. Future studies with a more individualized focus are needed to further understand which components of ACT work for whom on which outcome and how.

Significance

There remain people with chronic pain who do not benefit from acceptance and commitment therapy (ACT), and predicting treatment response is difficult. This is the first study to identify psychological flexibility (PF) profiles along multiple PF processes using latent class analysis, and the first longitudinal study to investigate PF profiles in relation to outcomes in ACT for chronic pain. The findings contribute to the understanding of theoretically consistent predictors of outcomes in ACT, which in turn can inform treatment development.