Attention to breath sensations does not engage endogenous opioids to reduce pain

Mindfulness Meditation and Placebo Modulate Distinct Multivariate Neural Signatures to Reduce Pain

BACKGROUND

Rather than a passive reflection of nociception, pain is shaped by the interplay between one's experiences, current cognitive-affective states, and expectations. The placebo response, a paradoxical yet reliable phenomenon, is postulated to reduce pain by engaging mechanisms shared with active therapies. It has been assumed that mindfulness meditation, practiced by sustaining nonjudgmental awareness of arising sensory events, merely reflects mechanisms evoked by placebo. Recently, brain-based multivariate pattern analysis has been validated to successfully disentangle nociceptive-specific, negative affective, and placebo-based dimensions of the subjective pain experience.

METHODS

To determine whether mindfulness meditation engages distinct brain mechanisms from placebo and sham mindfulness to reduce pain, multivariate pattern analysis pain signatures were applied across 2 randomized clinical trials that employed overlapping psychophysical pain testing procedures (49 °C noxious heat; visual analog pain scales) and distinct functional magnetic resonance imaging techniques (blood oxygen level-dependent; perfusion based). After baseline pain testing, 115 healthy participants were randomized into a 4-session mindfulness meditation (n = 37), placebo-cream conditioning (n = 19), sham mindfulness meditation (n = 20), or book-listening control (n = 39) intervention. After each intervention, noxious heat was administered during functional magnetic resonance imaging and each manipulation.

RESULTS

A double dissociation in the multivariate pattern analysis signatures supporting pain regulation was revealed by mindfulness meditation compared with placebo cream. Mindfulness meditation produced significantly greater reductions in pain intensity and pain unpleasantness ratings and nociceptive-specific and negative affective pain signatures than placebo cream, sham mindfulness meditation, and control interventions. The placebo-cream group significantly lowered the placebo-based signature.

CONCLUSIONS

Mindfulness meditation and placebo engaged distinct and granular neural pain signatures to reduce pain.

Mechanism of Action of Mindfulness-Based Interventions for Pain Relief-A Systematic Review

Background: Currently, no systematic evidence synthesis of the mechanism of action of mindfulness-based approaches exists for pain conditions. Aim: To identify and synthesize experimental and clinical studies examining aspects of the mechanism of action of mindfulness for pain relief. Methods: The following databases and search interfaces were searched: Embase (via Embase.com) and Medline (via PubMed). Additional references were identified via bibliographies of included studies. The following were the inclusion criteria applied: (1) original studies published in peer-reviewed journals, (2) in adult populations that (3) examined the mechanism of action of mindfulness meditation on pain outcomes or (4) provided conclusions regarding the potential mechanism of action of mindfulness meditation. The studies were selected by two independent reviewers. Discrepancies were resolved by discussion. Results: A total of 21 studies published in English met the inclusion criteria, of which 5 studies were clinical studies, which included patients with chronic pain, and 16 studies used experimental pain induction. The investigation into brain mechanisms through functional magnetic resonance imaging and diffusion tensor imaging revealed mindfulness meditation's ability to modulate brain activity, particularly in the anterior cingulate cortex, anterior insula, and orbitofrontal cortex, and to enhance structural and functional connectivity in regions associated with pain perception. Regarding the role of opioids, findings across five studies indicated that the analgesic effects of mindfulness are maintained even when opioid receptors are blocked, suggesting a nonopioidergic pathway for pain modulation. Pain perception studies highlighted that mindfulness practices foster pain acceptance and modify pain control beliefs, serving as key mediators in improving pain outcomes. For experienced versus novice mindfulness practitioners, results demonstrated that long-term practice enhances pain threshold and reduces pain unpleasantness through increased activity in salience and attentional control regions. Conclusion: This systematic review highlights mindfulness meditation as a multifaceted approach to pain management, utilizing mechanisms such as cognitive and emotional reappraisal, nonopioidergic pathways, and enhanced attention in control regions. It emphasizes the role of mindfulness in fostering pain acceptance and altering pain control perceptions, showcasing its broad impact on the neurological and experiential dimensions of pain. However, the predominance of studies on healthy subjects and methodological variations across experiments necessitates careful interpretation of the findings. The review calls for further research to explore the mechanisms of mindfulness in chronic pain populations more deeply, distinguishing the specific effects of mindfulness from nonspecific effects and expanding its applicability in clinical settings for chronic pain management.

Self-regulated analgesia in males but not females is mediated by endogenous opioids

Converging lines of preclinical and clinical research indicate that females, in stark contrast to males, display an increased prevalence of chronic pain. Females also demonstrate weaker analgesic efficacy in response to opioid therapies when compared with males. These sex-specific differences may be driven by dimorphic endogenous opioidergic responses. In rodent models, analgesia exhibited in males but not females was reversed by inhibiting endogenous opioidergic reception. In humans, the sex-specific endogenous system(s) supporting the direct attenuation of evoked pain has not been identified. To determine whether opioidergic blockade reverses self-regulated analgesia in males as compared to females, the present study combined two operationally analogous clinical trials (n = 98; 51 females and 47 males). In a double-blinded, counterbalanced study involving healthy (n = 39) and chronic low back pain (n = 59) populations, a high-dose naloxone (μ-, κ-, δ-opioid antagonist) vs. placebo-saline cross-over design (15 mg/kg bolus +0.1 mg/kg/h) tested the hypothesis that endogenous opioids mediate analgesia in males but not females. An 11-point visual analog scale (VAS) (0 = no pain; 10 = worst pain imaginable) evaluated pain ratings in response to noxious heat stimulation (49 °C; calf). After baseline pain testing, participants were randomized to a validated four-session mindfulness meditation or sham mindfulness meditation training intervention. Participants practiced their respective meditation during noxious heat, intravenous high-dose naloxone, and placebo saline, respectively. In males and females, meditation significantly lowered evoked pain during saline infusion. Intravenous naloxone inhibited analgesia in males, but pain relief was well preserved in females. The present findings indicate that endogenous opioids mediate self-regulated analgesia in males but not females and underscore the need to establish sex-specific pain therapeutics.

Pain, mindfulness, and placebo: a systematic review

Introduction

Pain is a complex phenomenon influenced by psychosocial variables, including the placebo effect. The effectiveness of mindfulness-based interventions (MBIs) for pain has been demonstrated in experimental studies and systematic reviews, but the mechanisms of action are only starting to be established. Whether the expectations of individuals experiencing pain can be manipulated during MBIs remains to be systematically evaluated, and what role placebo effects might play remains to be explored.

Methods

To evaluate the literature analyzing placebo effects in MBIs for pain, we performed a systematic review based on searches conducted in PubMed, Web of Science, and SCOPUS databases. Our search revealed a total of 272 studies, of which only 19 studies were included (10 acute pain and nine chronic pain), considering the inclusion and exclusion criteria related to expectations and placebo effects.

Results

From the 19 included studies, six measured placebo effects only in relation to the pharmacological intervention used in the study and not to an MBI.

Discussion

The results of the few studies that focused on the placebo effects of the MBIs indicate that placebo and expectations play a role in the MBIs' effects on pain. Although expectations and placebo effects are frequently discussed in the context of mindfulness and pain research, these results show that these factors are still not routinely considered in experimental designs. However, the results of the few studies included in this systematic review highlight a clear role for placebo and expectancy effects in the overall effects of MBIs for both acute and chronic pain, suggesting that routine measurement and further consideration in future studies are warranted. Additional research in this fascinating and challenging field is necessary to fully understand the connection between MBIs, placebo/expectations, and their effects on pain relief.

The role of endogenous opioids in mindfulness and sham mindfulness-meditation for the direct alleviation of evoked chronic low back pain: a randomized clinical trial

Chronic low back pain (cLBP) is the most prevalent chronic pain condition. There are no treatments that haven been found to directly assuage evoked cLBP. To this extent, mindfulness-meditation is a promising pain therapy. Yet, it is unclear if meditation can be utilized to directly attenuate evoked chronic pain through endogenous opioids. A double-blind, randomized, and placebo-controlled clinical trial with a drug crossover design examined if mindfulness-meditation, as compared to sham mindfulness-meditation, attenuated straight leg-raise test evoked chronic pain during intravenous (0.15 mg/kg bolus + 0.15 mg/kg/hour maintenance) naloxone (opioid antagonist) and placebo-saline infusion. Fifty-nine individuals with cLBP (mean age = 46 years; 30 females) completed all study procedures. After the pre-intervention pain testing session, patients were randomized to a four-session (20-min/session) mindfulness (n = 30) or sham mindfulness-meditation (n = 29) intervention. After the interventions, mindfulness and sham mindfulness-meditation were associated with significant reductions in back pain during saline and naloxone infusion when compared to rest (non-meditation) in response to the cLBP-evoking straight leg-raise test. These results indicate that meditation directly reduces evoked chronic pain through non-opioidergic processes. Importantly, after the interventions, the mindfulness group reported significantly lower straight leg-raise induced pain than the sham mindfulness-meditation group during rest (non-meditation) and meditation. Mindfulness and sham mindfulness-meditation training was also associated with significantly lower Brief Pain Inventory severity and interference scores. The pain-relieving effects of mindfulness meditation were more pronounced than a robust sham-mindfulness meditation intervention, suggesting that non-reactive appraisal processes may be uniquely associated with improvements in chronic low-back pain.Trial Registration: ClinicalTrials.gov identifier: NCT04034004.

Mindfulness-Based Interventions for Perioperative Pain Management and Opioid Risk Reduction Following Surgery: A Stepped Care Approach

Surgical procedures often improve health and function but can sometimes also result in iatrogenic effects, including chronic pain and opioid misuse. Due to the known risks of opioids and the physical, emotional, and financial suffering that often accompanies chronic pain, there has been a call for greater use of complementary non-pharmacological treatments like mindfulness-based interventions. Mindfulness can be broadly described as an attentional state involving moment-by-moment meta-awareness of thoughts, emotions, and body sensations. An expanding number of randomized clinical trials have found strong evidence for the value of mindfulness techniques in alleviating clinical symptomology relevant to surgical contexts. The purpose of this review is to examine the empirical evidence for the perioperative use of mindfulness interventions. We present a mindfulness-based stepped care approach that first involves brief mindfulness to treat preoperative pain and anxiety and prevent development of postoperative chronic pain or opioid misuse. More extensive mindfulness-based interventions are then provided to patients who continue to experience high pain levels or prolonged opioid use after surgery. Finally, we review psychophysiological mechanisms of action that may be integral to the analgesic and opioid sparing effects of mindfulness.

Divine resilience: Unveiling the impact of religious coping mechanisms on pain endurance in arab older adults battling chronic pain

BACKGROUND

Chronic pain diminishes the quality of life for many Older Adults individuals. Identifying effective coping methods to enhance pain resilience is imperative as populations age. Older Adults commonly use religious faith and spiritual practices to endure pain, yet little research has explored their impact on pain tolerance.

METHODS

This cross-sectional study examined relationships between positive/negative religious coping styles and pain endurance in 200 Arab elders with chronic pain. Participants completed the Brief Arab Religious Coping Scale, Numeric Pain Rating Scale, WHOQOL-BREF, and demographic/medical history questionnaires.

RESULTS

Quantitative analysis demonstrated significant positive associations between positive religious reappraisal and active spiritual coping with higher self-reported pain endurance (p<.05). Negative religious coping styles lacked meaningful relationships with pain tolerance. Multiple regression confirmed the unique effects of reappraisal and spiritual practice on improving pain resilience, controlling for covariates.

CONCLUSIONS

Outcomes align with perspectives highlighting multidimensional neurocognitive, emotional, and psychosocial pain relief from religious coping. Findings underscore integrating positive faith-based resources in biopsychosocial paradigms for Older Adult's pain management. Additional research should investigate causal pathways and contextual factors influencing religious coping effects on diverse Older Adult subgroups.

Self-regulation training for people with knee osteoarthritis: a protocol for a feasibility randomised control trial (MiNT trial)

Introduction

Knee osteoarthritis (OA) is a chronic secondary musculoskeletal pain condition resulting in disability, reduced quality of life, and high societal costs. Pain associated with knee OA is linked to increased sensitivity in sensory, cognitive, and emotional areas of the brain. Self-regulation training targeting brain functioning related to pain experience could reduce pain and its associated disability. Self-regulatory treatments such as mindfulness meditation (MM) and electroencephalography neurofeedback (EEG-NF) training improve clinical outcomes in people with knee OA. A feasibility clinical trial can address factors that could inform the design of the full trial investigating the effectiveness of self-regulation training programmes in people with knee OA. This clinical trial will evaluate the feasibility, safety, acceptability, experience and perceptions of the self-regulatory training programmes.

Methods

The proposed feasibility trial is based on a double-blind (outcome assessor and investigators), three-arm (MM usual care, EEG-NF + usual care and usual care control group) randomised controlled parallel clinical trial. Participants with knee OA will be recruited from the community and healthcare practices. A research assistant (RA) will administer both interventions (20-min sessions, four sessions each week, and 12 sessions over three successive weeks). Feasibility measures (participant recruitment rate, adherence to interventions, retention rate), safety, and acceptability of interventions will be recorded. An RA blinded to the group allocation will record secondary outcomes at baseline, immediately post-intervention (4th week), and 3 months post-intervention. The quantitative outcome measures will be descriptively summarised. The qualitative interviews will evaluate the participants' experiences and perceptions regarding various aspects of the trial, which includes identifying the barriers and facilitators in participating in the trial, evaluating their opinions on the research procedures, such as their preferences for the study site, and determining the level of acceptability of the interventions as potential clinical treatments for managing knee OA. Māori participant perceptions of how assessment and training practices could be acceptable to a Māori worldview will be explored. The interviews will be audio-recorded and analysed thematically.

Discussion

This trial will provide evidence on the feasibility, safety, and acceptability of the MM and EEG-NF training in people with knee OA, thus informing the design of a full randomised clinical control trial.

Vigilance to Painful Laser Stimuli is Associated with Increased State Anxiety and Tense Arousal

Introduction

Pain is frequently accompanied by enhanced arousal and hypervigilance to painful sensations. Here, we describe our findings in an experimental vigilance task requiring healthy participants to indicate when randomly timed moderately painful stimuli occur in a long train of mildly painful stimuli.

Methods

During a continuous performance task with painful laser stimuli (CPTpain), 18 participants rated pain intensity, unpleasantness, and salience. We tested for a vigilance decrement over time using classical metrics including correct targets (hits), incorrectly identified non-targets (false alarms), hit reaction time, and false alarm reaction time. We measured state anxiety and tense arousal before and after the task.

Results

We found a vigilance decrement across four 12.5-minute blocks of painful laser stimuli in hits [F3,51=2.91; p=0.043; time block 1>block 4 (t=2.77; p=0.035)]. Both self-report state anxiety (tpaired,17=3.34; p=0.0039) and tense arousal (tpaired,17=3.20; p=0.0053) increased after the task. We found a vigilance decrement during our laser pain vigilance task consistent with vigilance decrements found in other stimulus modalities. Furthermore, state anxiety positively correlated with tense arousal.

Discussion

CPTpain acutely increased tense arousal and state anxiety, consistent with previous results implicating the reciprocal interaction of state anxiety and acute painful sensations and the role of pain in augmenting tense arousal. These results may indicate a psychological process which predisposes the hypervigilant to developing greater acute pain, resulting in positive feedback, greater pain and anxiety.

Mechanisms of mindfulness in patients with migraine: Results of a qualitative study

OBJECTIVE

To understand the mechanisms of mindfulness' impact on migraine.

BACKGROUND

Promising mindfulness research demonstrates potential benefit in migraine, but no data-driven model exists from the lived experiences of patients that explains the mechanisms of mindfulness in migraine.

METHODS

Semi-structured qualitative interviews were conducted with adults with migraine who participated in two mindfulness-based stress reduction (MBSR) clinical trials (n = 43). Interviews were audio-recorded, transcribed, and summarized into a framework matrix with development of a master codebook. Constructivist grounded theory approach was used to identify themes/subthemes.

RESULTS

Participants who learned mindfulness techniques through MBSR experienced altered pain perception, altered response to migraine attacks and disease, increased awareness of external and internal experiences, improved overall well-being, and group benefits. Mindfulness resulted in earlier stress-body awareness and increased interoceptive awareness resulting in earlier attack recognition, leading to earlier and more effective management. Interictal factors of self-blame, guilt, and stigma decreased while migraine acceptance, hope, empowerment, self-efficacy, and self-compassion increased. Improved emotion regulation resulted in decreased fear of migraine, pain catastrophizing, anticipatory anxiety, and pain reactivity. Although taught as prevention, mindfulness was used both acutely and prophylactically. We created a conceptual model hypothesizing that MBSR skills led to an infusion of mindfulness in daily life, resulting in altered pain perception and experience, ultimately leading to improvement in overall well-being, which may positively feed back to the infusion of mindfulness in daily life. The therapeutic benefit of learning mindfulness in a group setting may moderate these effects.

CONCLUSIONS

This study identified several new potential mechanisms of mindfulness' effect on migraine. After learning MBSR skills, participants reported altered pain and migraine perception and experiences. Increased stress-body and interoceptive awareness resulted in earlier migraine awareness and treatment. Mindfulness may target important interictal factors that affect disease burden such as fear of migraine, pain catastrophizing, and anticipatory anxiety. This is the first data-driven study to help elucidate the mechanisms of mindfulness on migraine from patient voices and can help direct future research endeavors.

Disentangling self from pain: mindfulness meditation-induced pain relief is driven by thalamic-default mode network decoupling

ABSTRACT

For millenniums, mindfulness was believed to diminish pain by reducing the influence of self-appraisals of noxious sensations. Today, mindfulness meditation is a highly popular and effective pain therapy that is believed to engage multiple, nonplacebo-related mechanisms to attenuate pain. Recent evidence suggests that mindfulness meditation-induced pain relief is associated with the engagement of unique cortico-thalamo-cortical nociceptive filtering mechanisms. However, the functional neural connections supporting mindfulness meditation-based analgesia remain unknown. This mechanistically focused clinical trial combined functional magnetic resonance imaging with psychophysical pain testing (49°C stimulation and pain visual analogue scales) to identify the neural connectivity supporting the direct modulation of pain-related behavioral and neural responses by mindfulness meditation. We hypothesized that mindfulness meditation-based pain relief would be reflected by greater decoupling between brain mechanisms supporting appraisal (prefrontal) and nociceptive processing (thalamus). After baseline pain testing, 40 participants were randomized to a well-validated, 4-session mindfulness meditation or book-listening regimen. Functional magnetic resonance imaging and noxious heat (49°C; right calf) were combined during meditation to test study hypotheses. Mindfulness meditation significantly reduced behavioral and neural pain responses when compared to the controls. Preregistered (NCT03414138) whole-brain analyses revealed that mindfulness meditation-induced analgesia was moderated by greater thalamus-precuneus decoupling and ventromedial prefrontal deactivation, respectively, signifying a pain modulatory role across functionally distinct neural mechanisms supporting self-referential processing. Two separate preregistered seed-to-seed analyses found that mindfulness meditation-based pain relief was also associated with weaker contralateral thalamic connectivity with the prefrontal and primary somatosensory cortex, respectively. Thus, we propose that mindfulness meditation is associated with a novel self-referential nociceptive gating mechanism to reduce pain.

Conscious connected breathing with breath retention intervention in adults with chronic low back pain: protocol for a randomized controlled pilot study

BACKGROUND

Chronic pain is a major source of human suffering, and chronic low back pain (cLBP) is among the most prevalent, costly, and disabling of pain conditions. Due to the significant personal and societal burden and the complex and recurring nature of cLBP, self-management approaches that can be practiced at home are highly relevant to develop and test. The respiratory system is one of the most integrated systems of the body, and breathing is bidirectionally related with stress, emotion, and pain. Thus, the widespread physiological and psychological impact of breathing practices and breathwork interventions hold substantial promise as possible self-management strategies for chronic pain. The primary aim of the current randomized pilot study is to test the feasibility and acceptability of a conscious connected breathing with breath retention intervention compared to a sham control condition.

METHODS

The rationale and procedures for testing a 5-day conscious connected breathing with breath retention intervention, compared to a deep breathing sham control intervention, in 24 adults (18-65 years) with cLBP is described. Both interventions will be delivered using standardized audio recordings and practiced over 5 days (two times in-person and three times at-home), and both are described as Breathing and Attention Training to reduce possible expectancy and placebo effects common in pain research. The primary outcomes for this study are feasibility and acceptability. Feasibility will be evaluated by determining rates of participant recruitment, adherence, retention, and study assessment completion, and acceptability will be evaluated by assessing participants' satisfaction and helpfulness of the intervention. We will also measure other clinical pain, psychological, behavioral, and physiological variables that are planned to be included in a follow-up randomized controlled trial.

DISCUSSION

This will be the first study to examine the effects of a conscious connected breathing with breath retention intervention for individuals with chronic pain. The successful completion of this smaller-scale pilot study will provide data regarding the feasibility and acceptability to conduct a subsequent trial testing the efficacy of this breathing self-management practice for adults with cLBP.

TRIAL REGISTRATION

Clinicaltrials.gov, identifier NCT04740710 . Registered on 5 February 2021.

Reduced Pain by Mind-Body Intervention Correlates with Improvement of Shoulder Function in People with Shoulder Pain: A Randomized Controlled Trial

Meditation and acupressure-like stimulations have been shown to relieve pain. The aim of this study was to determine whether a short bout of mind-body intervention combined with meditation and acupressure-like stimulation was able to alleviate shoulder pain and improve its function in a short time window. Sixty-five adults with shoulder pain were recruited and randomly classified into two groups. One group participated in an intervention which consisted of acupressure-like stimulation and meditation over a 5 min period. The other group was instructed to rest during this time. A visual analog scale (VAS) pain score and objective constant scores were measured before and after intervention to determine shoulder pain and range of motion (ROM), respectively. A two-way repeated measures analysis of variance with Bonferroni correction and a regression analysis were performed. VAS pain, objective constant score, flexion, abduction, and external rotation score showed significant interactions between time and group. The pain intensity was significantly reduced, while flexion and abduction were significantly improved, in the experimental group compared to the control group, after the intervention. In addition, the change of flexion negatively correlated with the change of pain intensity in the experimental group, but not in the control group. These results show that a short-term application of mind-body intervention significantly alleviates shoulder pain and improves shoulder movement, suggesting its potential use as a therapy for people with shoulder pain.

Effects of Slow Deep Breathing on Acute Clinical Pain in Adults: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

Slow deep breathing (SDB) may help patients with acute pain. The primary aim of this systematic review and meta-analysis is to investigate the effects of SDB on acute pain. Secondary aims include investigating the effects of SDB on acute pain-related physical and emotional functioning. An a priori protocol was registered and a database search was conducted by a reference librarian. Randomized controlled trials (RCT) were eligible for inclusion and exclusion criteria included studies of SDB for non-pain indications and studies that applied SDB as a component of an encompassing intervention. The risk or bias was assessed using the Cochrane Collaboration's revised tool for assessing risk of bias in randomized trials. Meta-analysis was conducted using the random effects model. A total of 11 968 studies were screened and seven RCTs met inclusion criteria; five were judged to have low risk of bias. Meta-analysis of post-intervention pain scores demonstrated that SDB was associated with significantly lower pain scores compared with a control group, but with high levels of heterogeneity. Subgroup analyzes demonstrated that trials of burn pain were associated with a larger reduction in pain which partially explains the heterogeneity. Very low certainty evidence suggests that SDB may reduce acute pain intensity. Further research is needed to identify patients who are candidates for SDB and determine the best approach to deliver this therapy.

A Virtual Reality Meditative Intervention Modulates Pain and the Pain Neuromatrix in Patients with Opioid Use Disorder

OBJECTIVE

Standard of care for opioid use disorder (OUD) includes medication and counseling. However, there is an unmet need for complementary approaches to treat OUD patients coping with pain; furthermore, few studies have probed neurobiological features of pain or its management during OUD treatment. This preliminary study examines neurobiological and behavioral effects of a virtual reality-based meditative intervention in patients undergoing methadone maintenance treatment (MMT).

DESIGN

Prospective, non-blinded, single-arm, 12-week intervention with standardized assessments.

SETTING

Academic research laboratory affiliated with an on-site MMT clinic.

METHODS

Fifteen (11 female) MMT patients completed a virtual reality, therapist-guided meditative intervention that included breathing and relaxation exercisessessions were scheduled twice weekly. Assessments included functional magnetic resonance imaging (fMRI) of pain neuromatrix activation and connectivity (pre- and post-intervention), saliva cortisol and C-reactive protein (CRP) at baseline and weeks 4, 8 and 12; and self-reported pain and affective symptoms before and after each intervention session.

RESULTS

After each intervention session (relative to pre-session), ratings of pain, opioid craving, anxiety and depression (but not anger) decreased. Saliva cortisol (but not CRP) levels decreased from pre- to post-session. From pre- to post-intervention fMRI assessments, pain task-related left postcentral gyrus (PCG) activation decreased. At baseline, PCG showed positive connectivity with other regions of the pain neuromatrix, but this pattern changed post-intervention.

CONCLUSIONS

These preliminary findings demonstrate feasibility, therapeutic promise, and brain basis of a meditative intervention for OUD patients undergoing MMT.

The Role of Expectations and Endogenous Opioids in Mindfulness-Based Relief of Experimentally Induced Acute Pain

OBJECTIVE

Expectations contribute to cognitive pain modulation through opioidergically mediated descending inhibition. Mindfulness meditation reduces pain independent of endogenous opioids, engaging unique corticothalamocortical mechanisms. However, it remains unknown whether expectations for pain relief predict mindfulness-induced analgesia and if these expectations are modified by endogenous opioids.

METHODS

In this secondary analysis of previously published work, 78 pain-free participants (mean age, 27 ± 7 years; 50% women) were randomized to a four-session mindfulness meditation or book listening regimen. Expectations for intervention-induced pain relief were assessed before and after each intervention. Pain ratings were examined after meditation or rest (control group) during noxious heat (49°C) and intravenous administration of saline placebo or the opioid antagonist naloxone (0.15 mg/kg bolus + 0.1 mg kg-1 h-1 infusion.

RESULTS

Mindfulness significantly lowered pain during saline and naloxone infusion. Higher expected pain relief from mindfulness predicted lower pain intensity (r(40) = -0.41, p = .009). The relationship between meditation-related expectations and pain intensity reductions was exhibited during naloxone (r(20) = -0.76, p < .001) but not saline (r(20) = -0.22, p = .36). Expectations for book listening-based analgesia did not significantly predict pain changes during saline (r(20) = -0.37, p = .11) or naloxone (r(18) = 0.26, p = .30) in the control group.

CONCLUSIONS

These novel findings demonstrate a significant role for expectations in mindfulness-based pain relief. However, this role was minimal during saline and stronger during opioid blockade, despite similar pain reductions. This supports growing evidence that mindfulness engages multiple mechanisms to reduce pain, suggesting that mindfulness might be an effective pain-reducing technique even for individuals with low expectations for pain relief.

Keeping the Breath in Mind: Respiration, Neural Oscillations, and the Free Energy Principle

Scientific interest in the brain and body interactions has been surging in recent years. One fundamental yet underexplored aspect of brain and body interactions is the link between the respiratory and the nervous systems. In this article, we give an overview of the emerging literature on how respiration modulates neural, cognitive and emotional processes. Moreover, we present a perspective linking respiration to the free-energy principle. We frame volitional modulation of the breath as an active inference mechanism in which sensory evidence is recontextualized to alter interoceptive models. We further propose that respiration-entrained gamma oscillations may reflect the propagation of prediction errors from the sensory level up to cortical regions in order to alter higher level predictions. Accordingly, controlled breathing emerges as an easily accessible tool for emotional, cognitive, and physiological regulation.

To be mindful of the breath or pain: Comparing two brief preoperative mindfulness techniques for total joint arthroplasty patients

OBJECTIVE

Total joint arthroplasty (TJA) often reduces pain and improves function, but it is also a risk factor for the development of chronic pain and postoperative opioid use. To protect against these untoward postsurgical outcomes, TJA patients need better, non-pharmacological pain management strategies. This study compared two, promising, mindfulness-based pain management techniques.

METHOD

We conducted a single-site, three-arm, parallel-group randomized controlled study conducted at an orthopedic clinic among patients undergoing TJA of the knee or hip. TJA patients (N = 118, M age = 65, female = 73, Caucasian = 110) were randomized to either a preoperative mindfulness of breath (MoB), mindfulness of pain (MoP), or cognitive-behavioral pain psychoeducation (CB) intervention, approximately 3 weeks before surgery. Each intervention was delivered in a single, 20-min session during a 2-hr, preoperative education program. Change in pain intensity was the sole preoperative outcome. The postoperative outcomes, pain intensity, pain interference, and opioid use were assessed on the 2nd, 3rd, 7th, 14th, 21st, and 28th postoperative days.

RESULTS

MoB was found to most effectively decrease preoperative pain scores, F(2, 89) = 5.28, p = .007, while MoP resulted in the least amount of postoperative pain intensity, F(8, 94) = 3.21, p = .003, and interference, F(8, 94) = 2.52, p = .016). Both MoB and MoP decreased postoperative opioid use relative to CB, F(8, 83) = 16.66, p < .001.

CONCLUSION

A brief preoperative MBI may be able to prevent both postoperative pain and opioid use. Moreover, the MBIs used in this study are highly feasible, capable of being delivered by nearly any healthcare provider, and requiring minimal clinic time given their brevity. As such, embedding MBIs in surgical care pathways has considerable potential. (PsycInfo Database Record (c) 2021 APA, all rights reserved).

Transcutaneous Auricular Vagus Nerve Stimulation Combined With Slow Breathing: Speculations on Potential Applications and Technical Considerations

OBJECTIVES

Transcutaneous auricular vagus nerve stimulation (taVNS) is a relatively novel noninvasive neurostimulation method that is believed to mimic the effects of invasive cervical VNS. It has recently been suggested that the effectiveness of taVNS can be enhanced by combining it with controlled slow breathing. Slow breathing modulates the activity of the vagus nerve and is used in behavioral medicine to decrease psychophysiological arousal. Based on studies that examine the effects of taVNS and slow breathing separately, this article speculates on some of the conditions in which this combination treatment may prove effective. Furthermore, based on findings from studies on the optimization of taVNS and slow breathing, this article provides guidance on how to combine taVNS with slow breathing.

MATERIALS AND METHODS

A nonsystematic review.

RESULTS

Both taVNS and slow breathing are considered promising add-on therapeutic approaches for anxiety and depressive disorders, chronic pain, cardiovascular diseases, and insomnia. Therefore, taVNS combined with slow breathing may produce additive or even synergistic beneficial effects in these conditions. Studies on respiratory-gated taVNS during spontaneous breathing suggest that taVNS should be delivered during expiration. Therefore, this article proposes to use taVNS as a breathing pacer to indicate when and for how long to exhale during slow breathing exercises.

CONCLUSIONS

Combining taVNS with slow breathing seems to be a promising hybrid neurostimulation and behavioral intervention.

Brief mindfulness training can mitigate the influence of prior expectations on pain perception

BACKGROUND

Recent neuroimaging evidence suggests that mindfulness practice may mitigate the biasing influence of prior cognitive and emotional expectations on pain perception. The current study tested this hypothesis using a pain-cueing paradigm, which has reliably been shown to elicit conditioned hypoalgesic and hyperalgesic effects. Specifically, we aimed to investigate whether the instructed use of a mindfulness compared to a suppression strategy differentially modulates the magnitudes of conditioned hypoalgesia and hyperalgesia.

METHODS

Sixty-two healthy non-meditators were assigned to listen to either brief mindfulness or suppression instructions, in between the conditioning and testing phases of a pain-cueing task. Participants provided ratings of anticipatory anxiety, pain intensity and pain unpleasantness throughout the task. They also completed trait and state self-report measures of mindfulness and pain catastrophizing.

RESULTS

Results indicated that the paradigm was successful in inducing conditioned hyperalgesic and hypoalgesic effects. Importantly, while we found evidence of cue-induced hyperalgesia in both groups, only the suppression group reported cue-induced hypoalgesia. No group differences in pain ratings were found for unconditioned (novel-cued) stimuli.

CONCLUSIONS

These findings provide partial support for recently proposed predictive processing models, which posit that mindfulness may lead to a prioritization of current sensory information over previous expectations. We explore potential explanations for the asymmetrical group differences in conditioned hypoalgesia versus conditioned hyperalgesia, and discuss our results in light of recent neuroimaging insights into the neuropsychological mechanisms of mindfulness and expectancy-driven pain modulation.

SIGNIFICANCE

The current study provides novel insights into the working mechanisms of mindfulness-driven pain modulation. Our data suggest that brief mindfulness training may reduce the influence of prior beliefs and expectations on pain perception. This finding adds to growing evidence suggesting that mindfulness may alleviate pain via neuropsychological mechanisms opposite to those typically observed in conditioning/placebo procedures and other cognitive manipulations. These unique mechanisms underline the potential of mindfulness as an alternative to traditional cognitive pain regulatory strategies.

Pain and Interoceptive Awareness Outcomes of Chronic Pain Patients With Spinal Cord Stimulation

OBJECTIVES

Meditation has been shown to improve outcomes for chronic pain by increasing patients' awareness of their own bodies. Some patients have an innate ability to leverage their mind-body connection, and this interoceptive awareness may aid them in garnering pain relief. We explored whether spinal cord stimulation (SCS) patients with greater innate awareness had better outcomes.

MATERIALS AND METHODS

We contacted 30 thoracic SCS patients with baseline and postoperative pain, psychological, and disability outcomes to complete the Multidimensional Assessment of Interoceptive Awareness (MAIA) survey. MAIA distinguishes between beneficial and maladaptive aspects of the perception of body sensations via six positive subscales (noticing, attention regulation, emotional awareness, self-regulation, body listening, and trusting) and two negative subscales (not distracting, not worrying). MAIA subscales and positive/negative groups were correlated with percentage change in Numerical Rating Scale (NRS), Oswestry Disability Index (ODI), Beck's Depression Inventory (BDI), Pain Catastrophizing Scale (PCS), and McGill Pain Questionnaire (MPQ).

RESULTS

Patients included 14 males/16 females with a mean age of 58. At a mean follow-up of 14.13 months (range 6-26), NRS, ODI, BDI, PCS, and MPQ showed improvements. Positive traits correlated with improvements in pain (MAIA-self regulation with NRS-worst [p = 0.018], NRS-least [p = 0.042], NRS-average [p = 0.006], NRS-current [p = 0.001]; MAIA-body listening with MPQ-total [p = 0.016] and MPQ-sensory [p = 0.026]). Improvement in PCS-total was associated with higher scores in noticing (p = 0.002), attention regulation (p = 0.017), emotional awareness (p = 0.039), and trusting (p = 0.047). PCS-rumination correlated with MAIA-positive total (p = 0.012). In contrast, better attention regulation signified less improvement in ODI (p = 0.043) and MPQ affective (p = 0.026).

CONCLUSIONS

Higher interoceptive awareness in SCS patients correlated with greater improvement following the procedure, particularly with regards to pain relief and pain catastrophizing. These findings suggest that patients with better mind-body connections may achieve greater pain relief following SCS in this patient population, thereby aiding providers in determining who may benefit from this intervention.