Behavioral Conceptualization and Treatment of Chronic Pain

From the lab to the clinic: Advancing pain exposure using principles of functional analysis

In this article, we use the example of pain exposure therapy to illustrate how behavioral pain treatments can be systematically personalized following the principles of functional analysis. Based on the fear-avoidance model, pain exposure therapy has evolved as a mechanistically-based treatment to modify the mechanism of avoidance learning with the aim to reduce disability levels. We first present experimental evidence on avoidance learning from a general psychological perspective. We then illustrate how functional analysis can help therapists understand and address individual drivers of pain avoidance behavior. Finally, we explore how the network theory can translate the principles of functional analysis into statistical parameters using intensive longitudinal data, potentially making exposure experiments more relevant to the daily lives of individuals.

Understanding the individual's transition from acute to chronic disabling pain: Opportunities for improved care

When acute pain persists, it is said to become chronic after 3 months. Considerable interest has focused on why acute pain appears to transition to chronic pain in some cases, but not all, especially when it becomes disabling. We examine our current understanding of the processes involved in the progression from an acute injury to disabling chronic pain. Rather than viewing this progression as a time dependent transition with specific static risk factors, we consider whether it might be more helpful to understand this evolution in terms of unique individual pathways. While brief self-report screening questionnaires assessing risk factors may enable us to stratify patients into risk levels, they do not provide information on the unique context and factors contributing to the disabling pain for each person. It is proposed that a 2-step process combining screening and individual assessment of those at high risk will enhance the prospect of both early identification and individually relevant interventions before more lasting changes emerge. Rather than being concerned with arbitrary time limits, it is argued that by aiming to understand the unique developmental pathway for those individuals identified as high risk, early, preventive interventions will be both viable and effective. Even so, there are barriers to the implementation of early assessment and matched treatments, and these remain a challenge for future research.

Enhancing psychological assessment and treatment of chronic pain: A research agenda for personalized and process-based approaches

The heterogeneity of chronic pain and stagnating improvements in treatment effectiveness have prompted calls for a shift toward personalized and process-based approaches to the assessment and treatment of chronic pain. As this opens a new line of research, several fundamental questions arise. We begin by defining key terms and reviewing attempts to personalize treatment to date. Despite progress in personalization, long-term effects remain unclear. Existing studies are limited by group-based approaches that overlook individual variability. Future research should use idiographic methods and process-based therapy to tailor interventions to individual needs. A person- and process-oriented research agenda is needed that combines ambulatory assessment, network modeling, and single-case designs to advance personalized treatments for chronic pain and improve clinical decision-making.

Understanding the Pain Experience and Treatment Considerations Along the Spectrum of Peripheral Artery Disease: A Scientific Statement From the American Heart Association

Peripheral artery disease (PAD) is an atherosclerotic condition that affects a growing number of individuals worldwide, with estimates exceeding 220 million. One of the central hallmarks of PAD is lower extremity pain, which may present as intermittent claudication and atypical leg pain, and, in more severe cases, ischemic rest pain, neuropathic pain, or phantom limb pain in those who underwent amputation. Although the majority of individuals with PAD may experience pain that is chronic in nature, the pathogenesis and phenomenology of pain may differ. Nociceptive, inflammatory, and neuropathic mechanisms all play a role in the generation of pain. Pain in PAD results in severe disability and can copresent with distress, sickness behaviors such as avoidance and further deconditioning, and concomitant depression, anxiety, and addiction secondary to opioid use. These factors potentially lead to chronic pain interacting with a multitude of domains of functioning, including physical, emotional, and behavioral. Whereas pain is a normal adaptive response, self-defeating behaviors and cognitions contribute to the persistence or worsening of the chronic pain experience, disability, and distress. Much remains unknown about the phenomenology of pain in PAD and its clinical subgroups and how it affects outcomes. Borrowing from other chronic pain syndromes, multimodal pain management strategies that emphasize a biopsychosocial model have generated a solid evidence base for the use of cognitive behavioral approaches to manage pain. Multimodal pain management in PAD is not the norm, but theoretical pathways and road maps for further research, assessment, and clinical implementation are presented in this scientific statement.

Is personalization of psychological pain treatments necessary? Evidence from a Bayesian variance ratio meta-analysis

ABSTRACT

This is the first study to empirically determine the potential for data-driven personalization in the context of chronic primary pain (CPP). Effect sizes of psychological treatments for individuals with CPP are small to moderate on average. Aiming for better treatment outcomes for the individual patient, the call to personalize CPP treatment increased over time. However, empirical evidence that personalization of psychological treatments can optimize treatment outcomes in CPP is needed. This study seeks to estimate heterogeneity of treatment effect for cognitive behavioral therapy (CBT) as the psychological treatment approach for CPP with the greatest evidence base. For this purpose, a Bayesian variance ratio meta-regression is conducted using updated data from 2 recently published meta-analyses with randomized controlled trials comparing CBT delivered face-to-face to treatment-as-usual or waiting list controls. Heterogeneity in patients with CPP would be reflected by a larger overall variance in the post-treatment score compared with the control group. We found first evidence for an individual treatment effect in CBT compared with the control group. The estimate for the intercept was 0.06, indicating a 6% higher variance of end point values in the intervention groups. However, this result warrants careful consideration. Further research is needed to shed light on the heterogeneity of psychological treatment studies and thus to uncover the full potential of data-driven personalized psychotherapy for patients with CPP.A Bayesian variance ratio meta-regression indicates empirical evidence that data-driven personalized psychotherapy for patients with chronic primary pain could increase effects of cognitive behavioral therapy.

A multidisciplinary pain management program for patients with chronic low back pain: a randomized, single-blind, controlled, feasibility study

BACKGROUND

Multidisciplinary programs are the first recommendation for non-specific chronic low-back pain, but implementing this type of program is complicated to get up and running. The primary aim of this study was to assess the feasibility and appropriateness of the PAINDOC multidisciplinary program for subjects with chronic low-back pain. The secondary objectives were to evaluate the decrease in pain intensity, pain-related disability and pain catastrophizing, as well as the improvement in quality of life with this program. Furthermore, another of the secondary objectives was to calculate the sample size for a future randomized clinical trial.

METHODS

This study was conducted in a hospital pain unit using two successive recruitment waves. First, the feasibility outcomes (recruitment, completion, and drop-out rates) of a 5-month non-random prospective cohort (n = 227) were recorded. Then, the clinical outcomes (pain intensity, quality of life, disability, and pain catastrophizing) were recorded from a prospective, controlled, two-armed and single-blind feasibility study (ClinicalTrials.gov, NCT05974072). It included 41 participants that were randomly allocated to either the pharmacological treatment (n = 21) arm or PAINDOC program (n = 20) arm.

RESULTS

The recruitment rate was 66%, with the completion rate standing at 80.7% and the drop-out rate at 19.3%. Significant differences and a medium size effect were observed between groups in terms of pain intensity (p = .017, r = .408) at the 4-month follow-up. The intragroup analysis of the PAINDOC group revealed significant lessening in pain intensity (p = < 0.001) and improvements in quality of life (p = .030).

CONCLUSIONS

This study showed that the PAINDOC multidisciplinary program is a feasible treatment for patients with non-specific chronic low-back pain. Furthermore, the exploratory results of this study suggest that it could be an effective treatment to reduce pain intensity and improve on self-reported quality of life in these patients, although a future randomized clinical trial is needed to determine its effectiveness.

TRIAL REGISTRATION

NCT05974072 (registration date July 11, 2023; retrospectively registered; ClinicalTrials.gov).

How to personalise cognitive-behavioural therapy for chronic primary pain using network analysis: study protocol for a single-case experimental design with multiple baselines

INTRODUCTION

Cognitive-behavioural therapy (CBT) is an effective treatment for chronic primary pain (CPP), but effect sizes are small to moderate. Process orientation, personalisation, and data-driven clinical decision-making might address the heterogeneity among persons with CPP and are thus promising pathways to enhance the effectiveness of CBT for CPP. This study protocol describes one approach to personalise CBT for CPP using network analysis.

METHODS AND ANALYSIS

A single-case experimental design with multiple baselines will be combined with ecological momentary assessment (EMA). Feasibility and acceptance of the study procedure will be demonstrated on a sample of n=12 adults with CPP in an outpatient clinic. In phase A, participants complete 21 days of EMA, followed by the standard diagnostic phase of routine clinical care (phase B). Person-specific, process-based networks are estimated based on EMA data. Treatment targets are selected using mean ratings, strength and out-strength centrality. After a second, randomised baseline (phase A'), participants will receive 1 out of 10 CBT interventions, selected by an algorithm matching targets to interventions, in up to 10 sessions (phase C). Finally, another EMA phase of 21 days will be completed to estimate a post-therapy network. Tau-U and Hedges' g are used to indicate individual treatment effects. Additionally, conventional pain disability measures (Pain Disability Index and the adapted Quebec Back Pain Disability Scale) are assessed prior, post, and 3 months after phase C.

ETHICS AND DISSEMINATION

Ethical considerations were made with regard to the assessment-induced burden on the participants. This proof-of-concept study may guide future studies aiming at personalisation of CBT for CPP as it outlines methodological decisions that need to be considered step by step. The project was approved by the local ethics committee of the psychology department of University Kaiserslautern-Landau (#LEK-457). Participants gave their written informed consent prior to any data assessment and app installation. The results of the project will be published, presented at congresses, and relevant data will be made openly accessible via the Open Science Framework (OSF).

TRIAL REGISTRATION NUMBER

NCT06179784.

Topographically selective motor inhibition under threat of pain

ABSTRACT

Pain-related motor adaptations may be enacted predictively at the mere threat of pain, before pain occurrence. Yet, in humans, the neurophysiological mechanisms underlying motor adaptations in anticipation of pain remain poorly understood. We tracked the evolution of changes in corticospinal excitability (CSE) as healthy adults learned to anticipate the occurrence of lateralized, muscle-specific pain to the upper limb. Using a Pavlovian threat conditioning task, different visual stimuli predicted pain to the right or left forearm (experiment 1) or hand (experiment 2). During stimuli presentation before pain occurrence, single-pulse transcranial magnetic stimulation was applied over the left primary motor cortex to probe CSE and elicit motor evoked potentials from target right forearm and hand muscles. The correlation between participants' trait anxiety and CSE was also assessed. Results showed that threat of pain triggered corticospinal inhibition specifically in the limb where pain was expected. In addition, corticospinal inhibition was modulated relative to the threatened muscle, with threat of pain to the forearm inhibiting the forearm and hand muscles, whereas threat of pain to the hand inhibited the hand muscle only. Finally, stronger corticospinal inhibition correlated with greater trait anxiety. These results advance the mechanistic understanding of pain processes showing that pain-related motor adaptations are enacted at the mere threat of pain, as sets of anticipatory, topographically organized motor changes that are associated with the expected pain and are shaped by individual anxiety levels. Including such anticipatory motor changes into models of pain may lead to new treatments for pain-related disorders.

About Distress in Chronic Pain Conditions: A Pre-Post Study on the Effectiveness of a Mindfulness-Based Intervention for Fibromyalgia and Low Back Pain Patients

Chronic pain (CP) affects about 30% of the global population and poses significant challenges to individuals and healthcare systems worldwide. The interactions between physiological, psychological, and social factors are crucial in the onset and development of CP conditions. This study aimed to evaluate the effectiveness of mindfulness-based intervention, examining its impact on perceived stress (PSS), depression and anxiety (BDI-II, PGWBI/DEP, SAS, STAI Y), sleep quality (PSQI), and mindfulness abilities (MAAS) in individuals with CP. Participants (N = 89, 84.3% female) underwent one of two diagnoses [fibromyalgia (FM) or low back pain (LBP)] and took part in an MBSR intervention. The mindfulness program proved effective in reducing PSQI scores (F = 11.97; p < 0.01) over time, independently of the type of diagnosis. There was also a marginal increase in trait mindfulness as measured by MAAS (F = 3.25; p = 0.07) in both groups. A significant difference between the two groups was found for the effect on PSS: F (1,87) = 6.46; p < 0.05. Mindfulness practice also reduced anxiety in FM and depressive symptoms in LBP, indicating a reduction in psychological distress among participants. Our findings suggest that mindfulness-based interventions may offer promising avenues for personalized pain management in clinical settings.

Pain resilience dimensions and regional gray matter volume as risk factors for poor outcomes of chronic pain: a prospective cohort study

BACKGROUND

Pain resilience and regional gray matter volume (rGMV) are established correlates of adaptation to chronic pain within cross-sectional studies. Extending such work, this prospective cohort study tested the status of baseline pain resilience dimension scores and rGMV as risk factors for subsequent exacerbations in chronic pain disability and intensity.

METHODS

142 adults with chronic musculoskeletal pain completed an initial assessment comprising a structural magnetic resonance imaging scan and self-report measures of cognitive/affective positivity and behavioral perseverance pain resilience dimensions, disability, pain intensity, and demographics. Disability and pain intensity were outcomes re-assessed at a 6-month follow-up. The impact of pain resilience dimension scores and identified rGMV sites on follow-up outcomes was examined after controlling for other baseline correlates of outcomes. Mediating effects of identified rGMV sites on pain resilience dimension-follow-up outcome relations were also evaluated.

RESULTS

Aside from the significant multivariate effect of lower behavioral perseverance and cognitive/affective positivity scores, augmented left precuneus, temporal pole, superior temporal gyrus (STG), and precentral gyrus rGMV combined to predict higher follow-up disability levels, independent of covariates. Higher left fusiform gyrus rGMV levels predicted follow-up exacerbations in pain intensity, but pain resilience dimension scores did not. Finally, left precuneus and left temporal pole STG rGMV partially mediated cognitive/affective positivity-follow-up disability relations.

CONCLUSIONS

Findings underscore deficits in pain resilience and increased rGMV as potential risk factors for poorer subsequent outcomes of chronic musculoskeletal pain and provide foundations for further prospective extensions as well as targeted intervention research.

New Insight into Neuropathic Pain: The Relationship between α7nAChR, Ferroptosis, and Neuroinflammation

Neuropathic pain, which refers to pain caused by a lesion or disease of the somatosensory system, represents a wide variety of peripheral or central disorders. Treating neuropathic pain is quite demanding, primarily because of its intricate underlying etiological mechanisms. The central nervous system relies on microglia to maintain balance, as they are associated with serving primary immune responses in the brain next to cell communication. Ferroptosis, driven by phospholipid peroxidation and regulated by iron, is a vital mechanism of cell death regulation. Neuroinflammation can be triggered by ferroptosis in microglia, which contributes to the release of inflammatory cytokines. Conversely, neuroinflammation can induce iron accumulation in microglia, resulting in microglial ferroptosis. Accumulating evidence suggests that neuroinflammation, characterized by glial cell activation and the release of inflammatory substances, significantly exacerbates the development of neuropathic pain. By inhibiting microglial ferroptosis, it may be possible to prevent neuroinflammation and subsequently alleviate neuropathic pain. The activation of the homopentameric α7 subtype of the neuronal nicotinic acetylcholine receptor (α7nAChR) has the potential to suppress microglial activation, transitioning M1 microglia to an M2 phenotype, facilitating the release of anti-inflammatory factors, and ultimately reducing neuropathic pain. Recent years have witnessed a growing recognition of the regulatory role of α7nAChR in ferroptosis, which could be a potential target for treating neuropathic pain. This review summarizes the mechanisms related to α7nAChR and the progress of ferroptosis in neuropathic pain according to recent research. Such an exploration will help to elucidate the relationship between α7nAChR, ferroptosis, and neuroinflammation and provide new insights into neuropathic pain management.

Psychological risk factors of somatic symptom disorder: A systematic review and meta-analysis of cross-sectional and longitudinal studies

OBJECTIVE

Current diagnostic concepts of somatic symptom disorder (SSD) in DSM-5 and bodily distress disorder (BDD) in ICD-11 require certain psychological criteria, but researchers have called for further specification. Therefore, in a first step, this systematic review and meta-analysis aimed to summarize the current evidence on psychological factors associated with SSD/BDD and/or disorder-relevant clinical outcomes such as symptom severity and impairment.

METHODS

Psychological factors were systematically searched using Pubmed, Cochrane Library and Psycinfo via EBSCO. Studies providing original data in English or German, after 2009 were included. Cross-sectional, cohort and case-control studies investigating at least one psychological factor in individuals with SSD/BDD in the context of disorder-relevant outcomes were included.

RESULTS

Forty-three eligible studies (n = 3760 patients) in SSD (none in BDD) provided data on at least one psychological factor, 37 in case-control format, 10 cross-sectional and 5 longitudinal. Meta-analyses of the case-control studies found patients with SSD to be more impaired by depression (SMD = 1.80), anxiety (SMD = 1.55), health anxiety (SMD = 1.31) and alexithymia (SMD = 1.39), compared to healthy controls. Longitudinal results are scarce, mixed, and require refining, individual studies suggest self-concept of bodily weakness, anxiety and depression to be predictive for persistent SSD and physical functioning.

CONCLUSION

This review provides a detailed overview of the current evidence of psychological factors in relation to SSD/BDD. Future studies on SSD and BDD should include under-studied psychological factors, such as negative affect, fear avoidance, or emotion regulation. More longitudinal studies are needed to assess the predictive value of these factors.

Elaboration and validation of a novelty nomogram for the prognostication of anxiety susceptibility in individuals suffering from low back pain

Low back pain (LBP) constitutes a distressing emotional ordeal and serves as a potent catalyst for adverse emotional states, notably anxiety. We dedicated to discerning methodologies for identifying patients who are predisposed to heightened levels of anxiety and pain. A self-assessment questionnaire was administered to patients afflicted with LBP. The pain scores were subjected to analysis in conjunction with anxiety scores, and a clustering procedure was executed using the scientific k-means methodology. Subsequently, six machine learning algorithms, including Logistics Regression (LR), K-Nearest Neighbor (KNN), Decision Tree (DT), Support Vector Machine (SVM), Random Forest (RF), and Extreme Gradient Boosting (XGB), were employed. Next, five pertinent variables were identified, namely Age, Course, Body Mass Index (BMI), Education, and Marital status. Furthermore, a LR model was utilized to construct a nomogram, which was subsequently subjected to assessment for discrimination, calibration, and evaluation of its clinical utility. As a result, 599 questionnaires were valid (effective rate: 99 %). The correlation analysis revealed a significant association between anxiety and pain scores (r = 0.31, P < 0.001). LBP patients could be divided into two clusters, Cluster1 had higher pain scores (P < 0.05) and SAS scores (P < 0.001). The proposed nomogram demonstrated an area under the receiver operating characteristics curve (ROC) of 0.841 (95 %CI: 0.804-0.878) and 0.800 (95 %CI: 0.733-0.867) in the training and test groups, respectively. Briefly, the established nomogram has demonstrated remarkable proficiency in discerning individuals afflicted with LBP who are at a heightened risk of experiencing anxiety.

Investigating the Impact of Stress on Pain: A Scoping Review on Sense of Control, Social-Evaluative Threat, Unpredictability, and Novelty (STUN Model)

Background

Stress can have paradoxical effects on pain, namely hyperalgesia and hypoalgesia. Four situational characteristics activate the hypothalamic-pituitary-adrenal axis, leading to a physiological stress response: lacking Sense of control, social-evaluative Threat, Unpredictability and Novelty (STUN). This scoping review reports on the types of evidence published on the effects of STUN characteristics on pain outcomes.

Databases/Data Treatment

Searches of primary electronic databases were performed to identify articles published on adults between 1990 and 2021 that contained search terms on pain and stress/STUN characteristics. A total of 329 articles were included in the analysis.

Results

Only 3.3% of studies examined simultaneously >1 STUN component. Almost all observational studies (177/180) examined the association between perceived stress and pain without measuring physiological stress responses. Of the 130 experimental studies, 78 (60.0%) manipulated stressful characteristics through nociception, and only 38.5% assessed if/how stress manipulation impacted perceived stress.

Conclusion

There is a clear lack of integration of the characteristics that trigger a physiological stress response in the pain field. Only 3.3% of studies examined simultaneously more than one STUN component and there is an unequal attention given to individual components of the STUN framework. Recommendations for future research include selection of stress manipulations/measurements that are more precisely inducing/reflecting neurobiological mechanisms of stress responses to insure valid integration of scientific knowledge.

Landau model for illustrating the learning and unlearning process of nociplastic pain

Recent advancements in understanding the consolidation of nociplastic pain point to a complex, non-conscious learned process of threat perception. Neurobiological pain education is emerging as a promising approach to unlearn nociplastic pain, supported by biopsychosocial tools such as exposure to movement, mindfulness, and group sharing formats. However, this approach is still not well-known among clinicians and the society at large, creating a communication problem that unfortunately perpetuates the suffering of patients. Herein, we propose a Landau model to describe the learning and unlearning process of nociplastic pain, aiming to clarify this complex situation and facilitate communication across different sectors of the society. Nociplastic pain corresponds to a first-order transition, with attention more likely in the alert-protection state than in the trust-explore state. Two appealing results of the model are that the perception of the critical context depends on personal history regarding the symptom and that biopsychosocial loops are formed when there is alarming learned historical information about the symptom, along with confused and contradictory expert information, as seen in nocebo messages. Learning and unlearning in the model correspond to a chang in control parametrs that can weigh more on the alert-protection state, trust-explore state, uncertain state or neutral state. This description clarifies why neurobiological education is the foundational therapy from which others must be built to embody the accessible, clear, and trustworthy information.

Preference for Hedonic Goals in Fibromyalgia; Is It Always an Avoidance Mechanism? Looking the Relationship with Pain Acceptance from a Positive Psychology Perspective

The aim of this study was to analyze the effect of openness to experience on pain acceptance through positive affect (PA) considering the moderating role of preference for mood management goals in women with fibromyalgia (FM). A cross-sectional study (n = 231) was carried out. A simple mediation model and a moderate mediation model were conducted by SPSS macro-PROCESS. Results showed that PA mediated positively the effect of openness to experience on acceptance (B = 0.46, SE = 0.80, t = 5,59; 95% CI = [0.3016, 0.6298], p < .001) and that the contribution of openness to experience to PA varied at different values of mood management goals (medium: - .04; ß = .40, p < .001; high: .95; ß = .61, p<.001). Findings may serve as a foundation for tailored interventions to promote activity through acceptance focusing on PA and mood management goals among women with medium to high level of hedonic goals.

Corticotropin-releasing hormone neurons control trigeminal neuralgia-induced anxiodepression via a hippocampus-to-prefrontal circuit

Anxiety and depression are frequently observed in patients suffering from trigeminal neuralgia (TN), but neural circuits and mechanisms underlying this association are poorly understood. Here, we identified a dedicated neural circuit from the ventral hippocampus (vHPC) to the medial prefrontal cortex (mPFC) that mediates TN-related anxiodepression. We found that TN caused an increase in excitatory synaptic transmission from vHPCCaMK2A neurons to mPFC inhibitory neurons marked by the expression of corticotropin-releasing hormone (CRH). Activation of CRH+ neurons subsequently led to feed-forward inhibition of layer V pyramidal neurons in the mPFC via activation of the CRH receptor 1 (CRHR1). Inhibition of the vHPCCaMK2A-mPFCCRH circuit ameliorated TN-induced anxiodepression, whereas activating this pathway sufficiently produced anxiodepressive-like behaviors. Thus, our studies identified a neural pathway driving pain-related anxiodepression and a molecular target for treating pain-related psychiatric disorders.

Comparing physical therapy students' attitudes and beliefs regarding chronic low back pain and knee osteoarthritis: an international multi-institutional comparison between 2013 and 2020 academic years

BACKGROUND

In 2013, physical therapy students demonstrated low guideline-adherent recommendations regarding chronic low back pain (CLBP) for spinal pathology, activity, and work.

OBJECTIVES

To assess the differences in physical therapy students' attitudes, beliefs, and adherence to guideline recommendations regarding CLBP and knee osteoarthritis between 2013 and 2020.

METHODS

In 2013 and 2020, second and fourth-year physical therapy students were recruited from 6 Belgian and 2 Dutch institutions. Attitudes and beliefs regarding CLBP and knee OA were evaluated using the Pain Attitudes and Beliefs Scale for Physiotherapists (PABS-PT), the Health Care Providers' Pain and Impairment Relationship Scale (HC-PAIRS), and a questionnaire regarding therapeutic exercise and knee osteoarthritis. A clinical vignette was used to measure guideline-adherent recommendations regarding spinal pathology, activity, and work.

RESULTS

In 2013, 927 second-year and 695 fourth-year students; in 2020, 695 second-year and 489 fourth-year students; were recruited to participate in the study. Compared to 2013, students had less biomedical and stronger biopsychosocial attitudes and beliefs regarding CLBP, more guideline-adherent recommendations for activity, and more biopsychosocial beliefs regarding the benefits of exercise for patients with knee osteoarthritis in both the second and fourth year. Only fourth-year students in 2020 scored significantly better on HC-PAIRS and guideline-adherent recommendation relating to spinal pathology. No differences were found regarding work recommendations.

CONCLUSIONS

Between 2013 and 2020, physical therapy students made a positive shift towards a more biopsychosocial approach to CLBP and knee osteoarthritis management. Guideline-adherent recommendations for CLBP concerning activity improved, however, concerning work and spinal pathology, it remained low.

Reconceptualizing sensitization in pain: back to basics

Fillingim RB. Redefining sensitization could be a sensitive issue. PAIN Rep 2024;9:e1126.

The effect of psychological factors on pain outcomes: lessons learned for the next generation of research

Big data and machine learning techniques offer opportunities to investigate the effects of psychological factors on pain outcomes. Nevertheless, these advances can only deliver when the quality of the data is high and the underpinning causal assumptions are considered. We argue that there is room for improvement and identify some challenges in the evidence base concerning the effect of psychological factors on the development and maintenance of chronic pain. As a starting point, 3 basic tenets of causality are taken: (1) cause and effect differ from each other, (2) the cause precedes the effect within reasonable time, and (3) alternative explanations are ruled out. Building on these tenets, potential problems and some lessons learned are provided that the next generation of research should take into account. In particular, there is a need to be more explicit and transparent about causal assumptions in research. This will lead to better research designs, more appropriate statistical analyses, and constructive discussions and productive tensions that improve our science.

How physiotherapists attend to the human aspects of care when working with people with low back pain: a thematic analysis

Pain is a multidimensional experience. Physiotherapy has attempted to enhance earlier biomedical approaches to patient care through approaches like the 'biopsychosocial' model. Nevertheless, physiotherapy continues to focus on biomedical and/or behavioural aspects of care. We critically investigated how physiotherapists attend to human (psychosocial, emotional, existential, and moral) aspects of low back pain care. We co-analysed ethnographic data with researchers, patients, and physiotherapists using concepts of conforming, tinkering and abandoning 'scripts'. Data included observations of 28 physiotherapy interactions between 26 patients and 10 physiotherapists and 7 researcher-clinician dialogues. Analysis suggests when conforming to scripts, clinicians have difficulty recognising and responding to emotions; time pressure limited clinicians focus, and a biological focus often distracted from psychosocial aspects of people's back pain experiences. In contrast, tinkering with or abandoning scripts allowed space to broaden the focus. Drawing from theorists such as Butler (1999) and Gibson et al. (2020) our analysis contributes to health sociology, arguing that 'tinkering' with or 'abandoning' scripts can foster more humanistic, flexible and reflexive approaches to care. Although health sociologists have explored tinkering, abandoning is new; within physiotherapy, it encapsulates being able to respond with agility to non-physical elements of care without constraint from traditional ways of thinking and doing.

In search of conditioned pain: an experimental analysis

ABSTRACT

There is an ongoing debate about whether pain can be classically conditioned, but surprisingly, evidence is scarce. Here, we report 3 experiments investigating this idea. In a virtual reality task, healthy participants were approached and touched near or on their hand with a coloured pen (blue or yellow). During acquisition, participants learned that one of the colours of the pen (CS+) was predictive of a painful electrocutaneous stimulus (ECS) whereas the other coloured pen (CS-) was not. During the test phase, more frequent reports of experiencing an US when none was delivered ("false alarm") for the CS+ vs CS- qualified as evidence of conditioned pain. Notable differences between experiments were that the US was delivered when the pen touched a spot between the thumb and index finger (experiment 1; n = 23), when it virtually touched the hand (experiment 2; n = 28) and when participants were informed that the pen caused pain rather than simply predicting something (experiment 3; n = 21). The conditioning procedure proved successful in all 3 experiments: Self-reported fear, attention, pain, fear, and US expectancy were higher ( P < 0.0005) for the CS+ than the CS-. There was no evidence for conditioned pain in experiment 1, but there was some evidence in experiments 2 and 3. Our findings indicate that conditioned pain may exist, albeit most likely in rare cases or under specific situations. More research is needed to understand the specific conditions under which conditioned pain exists and the underlying processes (eg, response bias).

Sensorimotor Uncertainty of Immersive Virtual Reality Environments for People in Pain: Scoping Review

INTRODUCTION

Decision making and action execution both rely on sensory information, and their primary objective is to minimise uncertainty. Virtual reality (VR) introduces uncertainty due to the imprecision of perceptual information. The concept of "sensorimotor uncertainty" is a pivotal element in the interplay between perception and action within the VR environment. The role of immersive VR in the four stages of motor behaviour decision making in people with pain has been previously discussed. These four processing levels are the basis to understand the uncertainty that a patient experiences when using VR: sensory information, current state, transition rules, and the outcome obtained.

METHODS

This review examines the different types of uncertainty that a patient may experience when they are immersed in a virtual reality environment in a context of pain. Randomised clinical trials, a secondary analysis of randomised clinical trials, and pilot randomised clinical trials related to the scope of Sensorimotor Uncertainty in Immersive Virtual Reality were included after searching.

RESULTS

Fifty studies were included in this review. They were divided into four categories regarding the type of uncertainty the intervention created and the stage of the decision-making model.

CONCLUSIONS

Immersive virtual reality makes it possible to alter sensorimotor uncertainty, but studies of higher methodological quality are needed on this topic, as well as an exploration into the patient profile for pain management using immersive VR.

The combined effects of coping and pain interference on army readiness

Introduction

Chronic pain and associated interference with daily activities are common in the military and impact Force readiness. Chronic pain affects one-third of service members and is a leading cause of medical non-readiness (MNR) in the military. Research suggests that underlying psychological mechanisms related to trait coping styles and pain interference (PI) affect functional outcomes, but little research exists examining this relationship within an Army population. The purpose of this study was to examine the combined effects of PI and coping on U.S. Army soldier readiness by using annual well-being data from the Global Assessment Tool (GAT) and medical non-readiness (MNR) based on duty restriction records.

Methods

The sample comprised 866,379 soldiers who completed the GAT between 2014 and 2017 with no duty restrictions at the time of baseline GAT completion; subjects were observed through 2018 for duty restrictions. Parametric survival regression models with a Weibull distribution predicted demographic-adjusted hazards of MNR by dichotomized PI (no PI/PI) and beneficial/non-beneficial use of GAT coping components (good coping, bad coping, catastrophizing-flexibility, and catastrophizing-hopelessness). Incident MNR was evaluated for all duty restrictions, and stratified by selected body systems (upper extremity, lower extremity, psychiatric).

Results

Among soldiers with PI, hazards were higher in those reporting non-beneficial coping styles (bad coping, hopelessness) and lower in those reporting beneficial coping styles (good coping, flexibility). Across all coping styles, PI/coping interactions were particularly strong for catastrophizing-hopelessness and when examining MNR from psychiatric conditions.

Discussion

These findings suggest some synergistic associations between pain and coping that may impact pain-related occupational disability. Coping skills may be an effective interventional target for chronic pain reduction/prevention within military programs, such as the Master Resilience Training Course offered to soldiers in the Army. Further research should assess whether early coping style interventions can reduce pain-related outcomes.

Shifting the perspective: how positive thinking can help diminish the negative effects of pain

OBJECTIVES

The field of pain psychology has taken significant steps forward during the last decades and the way we think about how to treat chronic pain has radically shifted from a biomedical perspective to a biopsychosocial model. This change in perspective has led to a surge of accumulating research showing the importance of psychological factors as determinants for debilitating pain. Vulnerability factors, such as pain-related fear, pain catastrophizing and escape/avoidant behaviours may increase the risk of disability. As a result, psychological treatment that has emerged from this line of thinking has mainly focused on preventing and decreasing the adverse impact of chronic pain by reducing these negative vulnerability factors. Recently, another shift in thinking has emerged due to the field of positive psychology, which aims to have a more complete and balanced scientific understanding of the human experience, by abandoning the exclusive focus on vulnerability factors towards including protective factors.

METHODS

The authors have summarised and reflected on the current state-of-the-art of pain psychology from a positive psychology perspective.

RESULTS

Optimism is an important factor that may in fact buffer and protect against pain chronicity and disability. Resulting treatment approaches from a positive psychology perspective are aimed at increasing protective factors, such as optimism, to increase resilience towards the negative effects of pain.

CONCLUSIONS

We propose that the way forward in pain research and treatment is the inclusion of both vulnerability and protective factors. Both have unique roles in modulating the experience of pain, a finding that had been neglected for too long. Positive thinking and pursuing valued goals can make one's life gratifying and fulfilling, despite experiencing chronic pain.

Effects of False Feedback on Pain Tolerability Among Young Healthy Adults: Predictive Roles of Intentional Effort Investment and Perceived Pain Intensity

Purpose

Expectations and modification gained through critical learning influence pain perception. We tested how pain tolerability was influenced by the effects of orally delivered false feedback and participant status immediately prior to performing tasks.

Patients and Methods

A total of 125 healthy college students (69 females and 56 males) were randomly assigned to 3 groups (positive, negative, and control) to participate in two formal cold pressor tests (CPTs). Participants completed the same series of task-related questionnaires (perceived importance, intended effort, current affect, and self-efficacy) before each CPT. False performance feedback was delivered after completion of the baseline level CPT. After completion of each CPT, both pain intensity and pain tolerability (duration in ice water) were recorded.

Results

The results of linear mixed models revealed significant condition × time interactions on pain tolerability and task self-efficacy after controlling for individual variance as a random effect. Participants who received negative feedback exhibited increased pain tolerability without decreasing their self-efficacy, whereas participants who received positive feedback showed increased self-efficacy with no change in pain tolerability. A longer pain tolerance duration was also predicted by a more intentional investment of effort and a lower intensity of experienced pain as well as the effect of false feedback.

Conclusion

The research highlights the effect of powerful situational influences on laboratory-induced pain tolerance.

The cost-effectiveness of an indicated blended care intervention in primary care compared to usual care in patients with moderate persistent somatic symptoms

INTRODUCTION

Appropriate treatment for people with an increased risk for developing chronic Persistent Somatic Symptoms (PSS) is of great importance at an early stage to improve quality of life and prevent high costs for society.

OBJECTIVE

To evaluate the cost-effectiveness of an integrated blended care intervention compared to usual care for QALYs, subjective symptom impact and physical and mental health status in patients with moderate PSS.

METHODS

This economic evaluation was conducted alongside a 12-month prospective, multicenter cluster randomized controlled trial in Dutch primary care. 80 participants received the intervention and 80 participants received usual care. Seemingly unrelated regression analyzes were performed to estimate cost and effect differences. Missing data were imputed using multiple imputation. Bootstrapping techniques were used to estimate uncertainty.

RESULTS

We found no significant difference in total societal costs. Intervention, primary and secondary healthcare and absenteeism costs were higher for the intervention group. The ICER for QALYs demonstrated the intervention was on average less costly and less effective compared to usual care. For the subjective symptom impact and physical health, the ICER indicated that the intervention group was on average less costly and more effective. For mental health, the intervention was on average more costly and less effective.

CONCLUSION

We didn't find an integrated blended primary care intervention to be cost-effective compared to usual care. However, when looking on relevant, but specific outcome measures (subjective symptom impact and physical health) for this population, average costs are found to be lower and the effectiveness found to be higher.

Role of Immersive Virtual Reality in Motor Behaviour Decision-Making in Chronic Pain Patients

Primary chronic pain is a major contributor to disability worldwide, with an estimated prevalence of 20-33% of the world's population. The high socio-economic impact of musculoskeletal pain justifies seeking an appropriate therapeutic strategy. Immersive virtual reality (VR) has been proposed as a first-line intervention for chronic musculoskeletal pain. However, the growing literature has not been accompanied by substantial progress in understanding how VR exerts its impact on the pain experience and what neurophysiological mechanisms might be involved in the clinical effectiveness of virtual reality interventions in chronic pain patients. The aim of this review is: (i) to establish the state of the art on the effects of VR on patients with chronic pain; (ii) to identify neuroplastic changes associated with chronic pain that may be targeted by VR intervention; and (iii) to propose a hypothesis on how immersive virtual reality could modify motor behavioral decision-making through an interactive experience in patients with chronic pain.

Enhancing Exposure Treatment for Youths With Chronic Pain: Co-design and Qualitative Approach

BACKGROUND

Increasing the access to and improving the impact of pain treatments is of utmost importance, especially among youths with chronic pain. The engagement of patients as research partners (in contrast to research participants) provides valuable expertise to collaboratively improve treatment delivery.

OBJECTIVE

This study looked at a multidisciplinary exposure treatment for youths with chronic pain through the lens of patients and caregivers with the aim to explore and validate treatment change processes, prioritize and develop ideas for improvement, and identify particularly helpful treatment elements.

METHODS

Qualitative exit interviews were conducted with patients and caregivers at their discharge from 2 clinical trials (ClinicalTrials.gov NCT01974791 and NCT03699007). Six independent co-design meetings were held with patients and caregivers as research partners to establish a consensus within and between groups. The results were validated in a wrap-up meeting.

RESULTS

Patients and caregivers described that exposure treatment helped them better process pain-related emotions, feel empowered, and improve their relationship with each other. The research partners developed and agreed upon 12 ideas for improvement. Major recommendations include that pain exposure treatment should be disseminated more not only among patients and caregivers but also among primary care providers and the general public to facilitate an early referral for treatment. Exposure treatment should allow flexibility in terms of duration, frequency, and delivery mode. The research partners prioritized 13 helpful treatment elements. Most of the research partners agreed that future exposure treatments should continue to empower patients to choose meaningful exposure activities, break long-term goals into smaller steps, and discuss realistic expectations at discharge.

CONCLUSIONS

The results of this study have the potential to contribute to the refinement of pain treatments more broadly. At their core, they suggest that pain treatments should be disseminated more, flexible, and transparent.

Better Together. Group versus individual Cognitive-Behavioral Therapy for tinnitus: A Multiple-Baseline Single-Case Experimental Design

OBJECTIVES

Chronic tinnitus is effectively treated through cognitive-behavioral therapy (CBT). Both group and individual CBT for tinnitus are effective, but no study has directly compared the two. The current study explores group versus individual CBT for tinnitus.

DESIGN

A multiple-baseline single-case experimental design was employed to observe changes within/between individual and group treatments. Six participants started a 10-week CBT protocol and were equally divided into individual or group treatment. Participants were exchanged between treatments at random time points. Diary data included 14 variables on tinnitus experience (e.g. annoyance and distraction) and wellbeing (e.g. happiness and stress). Five male participants (59- to 67-year-old) completed treatment.

RESULTS

Randomization tests comparing means between individual and group treatments did not reveal significant differences. Analysis of data overlap and trend (Tau-U) revealed minor significant improvements for seven variables (50%) in group treatment as compared to individual treatment. Diminished happiness and activity levels were observed in participants who went from group to individual treatment.

CONCLUSIONS

Low effect sizes and homogeneity of sample restrict the generalizability of data. Group CBT indicated potential benefits when compared to individual CBT. Social learning may be an underlying process in group delivery boosting tinnitus recovery. Findings are limited to male patients with chronic disabling tinnitus.

180-degree immersive VR motion visualization in the treatment of haemophilic ankle arthropathy

BACKGROUND

Patients with haemophilic arthropathy suffer chronic pain that affects and restricts their quality of life. Visualization of movement through immersive virtual reality is used for pain management.

AIM

To evaluate the efficacy of 180-degree immersive VR motion visualization therapy in patients with haemophilic ankle arthropathy.

METHODS

Prospective, multicentre pilot study. Fifteen adult patients with bilateral haemophilic ankle arthropathy were recruited (mean age: 42.73 ± 12.36 years). The intervention lasted 4 weeks, with daily home sessions of 180-degree immersive motion visualization. The patients were given virtual reality glasses to use with their smartphones. From the YouTube mobile app® they accessed the recorded video with access from the He-Mirror App®. The study variables were joint state (Haemophilia Joint Health Score), pressure pain threshold (pressure algometer), muscle strength (dynamometry) and range of motion (goniometry). Three evaluations were performed: at baseline (T0), after the intervention (T1) and at the end of a 16-week follow-up period (T2).

RESULTS

No patient developed ankle hemarthrosis during the experimental phase. In the repeated measures analysis we found statistically significant differences in joint state (F = 51.38; η² _p = .63), pressure pain threshold of the lateral malleolus (F = 12.34; η² _p = .29) and range of motion (F = 11.7; η² _p = .28).

CONCLUSIONS

Therapy using immersive motion visualization does not cause hemarthrosis. This intervention can improve joint condition, pressure pain threshold and range of motion in patients with ankle arthropathy. Changes greater than the MDC were reported in more than 40% of patients for the variables pressure pain threshold, anterior tibialis strength and range of motion, which were considered clinically relevant.

Pavlovian-to-Instrumental Transfer across Mental Disorders: A Review

A mechanism known as Pavlovian-to-instrumental transfer (PIT) describes a phenomenon by which the values of environmental cues acquired through Pavlovian conditioning can motivate instrumental behavior. PIT may be one basic mechanism of action control that can characterize mental disorders on a dimensional level beyond current classification systems. Therefore, we review human PIT studies investigating subclinical and clinical mental syndromes. The literature prevails an inhomogeneous picture concerning PIT. While enhanced PIT effects seem to be present in non-substance-related disorders, overweight people, and most studies with AUD patients, no altered PIT effects were reported in tobacco use disorder and obesity. Regarding AUD and relapsing alcohol-dependent patients, there is mixed evidence of enhanced or no PIT effects. Additionally, there is evidence for aberrant corticostriatal activation and genetic risk, e.g., in association with high-risk alcohol consumption and relapse after alcohol detoxification. In patients with anorexia nervosa, stronger PIT effects elicited by low caloric stimuli were associated with increased disease severity. In patients with depression, enhanced aversive PIT effects and a loss of action-specificity associated with poorer treatment outcomes were reported. Schizophrenic patients showed disrupted specific but intact general PIT effects. Patients with chronic back pain showed reduced PIT effects. We provide possible reasons to understand heterogeneity in PIT effects within and across mental disorders. Further, we strengthen the importance of reliable experimental tasks and provide test-retest data of a PIT task showing moderate to good reliability. Finally, we point toward stress as a possible underlying factor that may explain stronger PIT effects in mental disorders, as there is some evidence that stress per se interacts with the impact of environmental cues on behavior by selectively increasing cue-triggered wanting. To conclude, we discuss the results of the literature review in the light of Research Domain Criteria, suggesting future studies that comprehensively assess PIT across psychopathological dimensions.

Changes in task-specific fear of movement and impaired trunk motor control by pain neuroscience education and exercise: A preliminary single-case study of a worker with low back pain

We report a case (a worker with low back pain) who was provided patient education and therapeutic exercise, and we performed a detailed kinematic analysis of his work-related activity over time. The subjects were one 28-year-old male worker with low back pain. In addition, to clearly identify impaired trunk movement during work-related activity in the low back pain subject, 20 age-matched healthy males (control group) were also included as a comparison subject. He received pain neurophysiology education and exercise instruction. We analyzed the subject's trunk movement pattern during a lifting task examined by a three-dimensional-motion capture system. In addition, task-specific fear that occurred during the task was assessed by the numerical rating scale. The assessment was performed at the baseline phase (4 data points), the intervention phase (8 data points), and the follow-up phase (8 data points), and finally at 3 and 8 months after the follow-up phase. No intervention was performed in the control group; they underwent only one kinematic evaluation at baseline. As a result, compared to the control group, the low back pain subject had slower trunk movement velocity (peak trunk flexion velocity = 50.21 deg/s, extension velocity = -47.61 deg/s), and his upper-lower trunk segments indicated an in-phase motion pattern (mean absolute relative phase = 15.59 deg) at baseline. The interventions reduced his pain intensity, fear of movement, and low back pain-related disability; in addition, his trunk velocity was increased (peak trunk flexion velocity = 82.89 deg/s, extension velocity = -77.17 deg/s). However, the in-phase motion pattern of his trunk motor control remained unchanged (mean absolute relative phase = 16.00 deg). At 8 months after the end of the follow-up, the subject's in-phase motion pattern remained (mean absolute relative phase = 13.34 deg) and his pain intensity had increased. This report suggests that if impaired trunk motor control remains unchanged after intervention, as in the course of the low back pain subject, it may eventually be related to a recurrence of low back pain symptoms.

The paradox of wellbeing: what happens among women with fibromyalgia? The effect of cognitive fusion

OBJECTIVE

Our study examined the 'paradox of wellbeing' among women with fibromyalgia and the role of cognitive fusion on wellbeing in relation to age.

METHODS

A total of 228 women diagnosed with fibromyalgia according to the American College of Rheumatology criteria were included. In order to explore the conditional effects of age in the moderation analyzes, as recommended in the PROCESS Macro, the 16th, 50th, and 84th percentiles were calculated. These percentiles define three age groups that we will call younger (from 30 to 53 years), middle-aged (from 54 to 60 years) and older women (from 61 to 78 years).

RESULTS

We found a 'paradox of wellbeing' among fibromyalgia patients which has not yet been reported: the older the patients, the higher scores on hedonic (positive affect) and eudaimonic (activities engagement) wellbeing. A moderation effect of age was found in the relationship between cognitive fusion and wellbeing (cognitive fusion showed negative associations with positive affect and activities engagement but not among older patients).

CONCLUSION

Our study underscores the need of personalized interventions for fibromyalgia patients to improve their wellbeing. Especially in younger and middle-aged patients, it would be of interest interventions in cognitive defusion through Acceptance and Commitment Therapy (ACT).

The role of intolerance of uncertainty when solving the exploration-exploitation dilemma

When making behavioral decisions, individuals need to balance between exploiting known options or exploring new ones. How individuals solve this exploration-exploitation dilemma (EED) is a key research question across psychology, leading to attempting to disentangle the cognitive mechanisms behind it. A potential predictive factor of performance in an EED is intolerance of uncertainty (IU), an individual difference factor referring to the extent to which uncertain situations are reported to be aversive. Here, we present the results of a series of exploratory analyses in which we tested the relationship between IU and performance in an EED task. For this, we compiled data from 3 experiments, in which participants received the opportunity to exploit different movements in order to avoid a painful stimulus and approach rewards. For decomposing performance in this task, we used different computational models previously employed in studies on the EED. Then, the parameters of the winning model were correlated with the scores of participants in the IU scale. Correlational and cluster analyses, within both frequentists and Bayesian frameworks, did not provide strong evidence for a relation between EED and IU, apart from the decay rate and the subscale "tendency to become paralyzed in the face of uncertainty". Given the theoretical relation between EED and IU, we propose research with different experimental paradigms.

Inflammatory Bowel Disease and Pain Interference: A Conceptual Model for the Role of Insomnia, Fatigue, and Pain Catastrophizing

Background

People with inflammatory bowel disease (IBD) commonly experience pain influenced by complex interactions among factors, including disease activity, sleep, psychopathology, and changes in pain processing pathways. Treatments for pain in IBD are limited, highlighting the need for research that explores modifiable factors linked to pain. The aim of this study was to investigate relationships among multiple patient factors and to construct a conceptual model for pain interference in IBD.

Methods

A cross-sectional survey of adults with IBD. Study domains included demographic, comorbidity, psychological, IBD, insomnia, fatigue, and pain features. Structural equation modeling (SEM) was used to examine relationships and interactions among active IBD, insomnia, fatigue, pain experiences (severity, catastrophizing, and interference), and additional patient factors (demographics and psychological).

Results

One hundred and seventy-four participants, aged 18-85 years, reported the presence of pain. Combining the questionnaire data using SEM resulted in a final model with an excellent fit (χ 2(8) = 9.579, P = .297, χ 2/N = 1.197, CFIN = 0.997, TLI = 0.987, RMSEA = 0.034). The presence of anxiety and depression was the additional patient factors to be retained in the path analysis. SEM results indicated that greater pain interference was directly influenced by greater fatigue, worse pain catastrophizing, and worse pain severity. Pain interference was indirectly impacted by IBD activity, worse insomnia, and the presence of depression and anxiety.

Conclusions

The proposed conceptual model highlights the role of multiple potentially modifiable factors, including insomnia, pain catastrophizing, and fatigue, contributing to worse pain interference in people with IBD.

Reward learning in the development and maintenance of chronic back pain

Treating and preventing chronic pain require our understanding of how it develops and maintains. Löffler et al. (2022)¹ demonstrate that distinct operant learning signals in the vmPFC-NAc pathway predict the development and maintenance of chronic back pain.

How expectancy violations facilitate learning to cope with pain - An experimental approach

BACKGROUND

Expectations of painful sensations constitute a core feature of chronic pain. An important clinical question is whether such expectations are revised when disconfirming experiences are made (e.g., less pain than expected). This study examined how people adjust their pain expectations when the experience of decreasing pain is expected vs. unexpected.

METHODS

In a novel randomized between-subjects design, a subclinical sample of people who frequently experience pain was provided with painful thermal stimulations. Unbeknownst to participants, the temperature applied was decreased from trial to trial. Based on the experimental instructions provided, this experience of decreasing pain was expected in one condition (expectation-confirmation; n = 34), whereas it was unexpected in another (expectation-disconfirmation; n = 39).

RESULTS

Perceived pain intensity was lower in the expectation-confirmation condition than in the expectation-disconfirmation condition (p = .014, η_p² = 0.083). The expectation-confirmation condition also showed a greater adjustment of their pain expectations than the expectation-disconfirmation condition (p = .046, η_p² = 0.047). Across groups, large expectation violations (i.e., less pain than expected) were associated with increases in pain tolerance and the ability to cope with pain at a one-week follow-up.

CONCLUSIONS

In terms of assimilation, perceived pain intensity was shaped in the direction of pain expectations. The greater adjustment of expectations in the expectation-confirming condition is consistent with a confirmation bias in pain perception. Though participants who experienced large discrepancies between expected and experienced pain were hesitant to adjust their pain expectations immediately, expectation violations increased their ability to cope with pain one week later, suggesting some beneficial longer-term effects of expectation violations.

How do psychologically based interventions for chronic musculoskeletal pain work? A systematic review and meta-analysis of specific moderators and mediators of treatment

Psychologically based interventions aim to improve pain-related functioning by targeting pain-related fears, cognitions and behaviors. Mediation and moderation analyses permit further examination of the effect of treatment on an outcome. This systematic review and meta-analysis aims to synthetize the evidence of specific mediators and moderators (i.e., treatment targets) of psychologically based treatment effects on pain and disability. A total of 28 mediation and 11 moderation analyses were included. Thirteen mediation studies were included in a meta-analysis, and the rest was narratively synthetized. Reductions in pain-related fear (indirect effect [IE]: -0.07; 95% confidence interval [CI]: -0.11, -0.04) and catastrophizing (IE: -0.07; 95%CI: -0.14, -0.00), as well as increases in self-efficacy (IE: -0.07; 95%CI: -0.11, -0.04), mediated effects of cognitive behavioral therapy on disability but not on pain intensity, when compared to control treatments. Enhancing pain acceptance (IE: -0.17; 95%CI: -0.31, -0.03) and psychological flexibility (IE: -0.30; 95%CI: -0.41, -0.18) mediated acceptance and commitment therapy effects on disability. The narrative synthesis showed conflicting evidence, which did not support a robust moderated effect for any of the examined constructs. Overall, the methodological quality regarding mediation was low, and some key pitfalls are highlighted alongside recommendations to provide a platform for future research.

Is Chronic Pain a Disease?

It was not until the twentieth century that pain was considered a disease. Before that it was managed medically as a symptom. The motivations for declaring chronic pain a disease, whether of the body or of the brain, include increasing its legitimacy as clinical problem and research focus worthy of attention from healthcare and research organizations alike. But 1 problem with disease concepts is that having a disease favors medical solutions and tends to reduce patient participation. We argue that chronic pain, particularly chronic primary pain (recently designated a first tier pain diagnosis in International Diagnostic Codes 11), is a learned state that is not intransigent even if it has biological correlates. Chronic pain is sometimes a symptom, and may sometimes be its own disease. But here we question the value of a disease focus for much of chronic pain for which patient involvement is essential, and which may need a much broader societal approach than is suggested by the disease designation. PERSPECTIVE: This article examines whether designating chronic pain a disease of the body or brain is helpful or harmful to patients. Can the disease designation help advance treatment, and is it needed to achieve future therapeutic breakthrough? Or does it make patients over-reliant on medical intervention and reduce their engagement in the process of recovery?

The Role of Walking in the Relationship between Catastrophizing and Fatigue in Women with Fibromyalgia

Walking is one of the most beneficial treatments for fibromyalgia patients. However, adherence to walking behavior is low due to the initially associated symptoms (including pain and fatigue). Although the association of catastrophism with greater symptoms is known, the results regarding fatigue have not always been consistent. Nevertheless, it is unknown whether the association between catastrophism and fatigue could, in turn, be conditioned by whether the patients walk or not. Therefore, our goal was to explore the moderating effect of walking on the association between catastrophizing and fatigue in patients with fibromyalgia. A cross-sectional study was carried out with 203 women with fibromyalgia. We used the Multidimensional Fatigue Inventory to assess fatigue and the Pain Catastrophizing Scale to assess pain catastrophizing (differentiating between its three dimensions). An ad hoc item was used to evaluate walking (moderator). Lower scores for fatigue and pain catastrophizing were found among patients who walked versus those who did not. Walking moderated the relationship between rumination and fatigue (Beta = 0.16, t = 1.96, p = 0.049) and between magnification and fatigue (Beta = 0.22, t = 21.83, p = 0.047). Helplessness showed no direct or interaction effect for fatigue. Nevertheless, higher rumination and magnification were associated with higher fatigue only in patients who walked. Therefore, to promote adherence to walking and reduce the effects of catastrophizing on fatigue, it seems necessary to manage rumination and magnification among patients who walk.

A functional subdivision within the somatosensory system and its implications for pain research

Somatosensory afferents are traditionally classified by soma size, myelination, and their response specificity to external and internal stimuli. Here, we propose the functional subdivision of the nociceptive somatosensory system into two branches. The exteroceptive branch detects external threats and drives reflexive-defensive reactions to prevent or limit injury. The interoceptive branch senses the disruption of body integrity, produces tonic pain with strong aversive emotional components, and drives self-caring responses toward to the injured region to reduce suffering. The central thesis behind this functional subdivision comes from a reflection on the dilemma faced by the pain research field, namely, the use of reflexive-defensive behaviors as surrogate assays for interoceptive tonic pain. The interpretation of these assays is now being challenged by the discovery of distinct but interwoven circuits that drive exteroceptive versus interoceptive types of behaviors, with the conflation of these two components contributing partially to the poor translation of therapies from preclinical studies.

Individual Patterns and Temporal Trajectories of Changes in Fear and Pain during Exposure In Vivo: A Multiple Single-Case Experimental Design in Patients with Chronic Pain

Exposure in vivo (EXP) is an effective treatment to reduce pain-related fear and disability in chronic pain populations. Yet, it remains unclear how reductions in fear and pain relate to each other. This single-case experimental design study attempted to identify patterns in the individual responses to EXP and to unravel temporal trajectories of fear and pain. Daily diaries were completed before, during and after EXP. Multilevel modelling analyses were performed to evaluate the overall effect. Temporal effects were scrutinized by individual regression analyses and determination of the time to reach a minimal clinically important difference. Furthermore, individual graphs were visually inspected for potential patterns. Twenty patients with chronic low back pain and complex regional pain syndrome type I were included. On a group level, both fear and pain were reduced following EXP. Individually, fear was significantly reduced in 65% of the patients, while pain in only 20%. A decrease in fear was seen mostly in the first weeks, while pain levels reduced later or remained unchanged. Daily measurements provided rich data on temporal trajectories of reductions in fear and pain. Overall, reductions in fear preceded pain relief and seemed to be essential to achieve pain reductions.

Neuroscientific evidence for pain being a classically conditioned response to trauma- and pain-related cues in humans

ABSTRACT

Psychological trauma is typically accompanied by physical pain, and posttraumatic stress disorder (PTSD) often co-occurs with chronic pain. Clinical reports suggest that pain after trauma may be part of a re-experiencing symptomatology. Classical conditioning can underlie visual re-experiencing since intrusions can occur as conditioned responses (CRs) to trauma-related cues. If individuals also experience pain to cues previously paired with, but not anymore inflicting nociceptive stimulation (CSs), conditioning could also explain re-experiencing of pain. Sixty-five participants underwent classical conditioning, where painful electrocutaneous stimulation and aversive film-clips served as unconditioned stimuli (USs) in a 2(pain/no pain)×2(aversive/neutral film) design. CSs were neutral pictures depicting contextual details from the films. One day later, participants were re-exposed to CSs during a memory-triggering-task (MTT). We assessed pain-CRs by self-report and an fMRI-based marker of nociceptive pain, the neurologic pain signature (NPS); and recorded spontaneous daily-life pain-intrusions with an e-diary. During conditioning, pain-signaling CSs elicited more self-reported-pain and NPS-responses than no-pain-signaling CSs. Possibly because the aversive-film masked differences in participants' responses to pain-signaling vs. no-pain-signaling CSs, pain-CRs during acquisition only emerged within the neutral-film condition. When participants were re-exposed to CSs during MTT, self-reported-pain-CRs during the neutral-film condition and, though more uncertain, NPS-CRs during the aversive-film condition persisted. Importantly, participants with stronger pain-CRs showed a greater probability and severity of experiencing spontaneous pain intrusions during daily-life. Our data support that pain can emerge as a CR with emotional and sensory components. Classical conditioning presents a possible mechanism explaining pain-intrusions, and more broadly, pain experienced without nociceptive input.