The role of affect in chronic pain: A systematic review of within-person symptom dynamics

Differences in anxiety, depression and pain experience among adults with chronic low back pain as a function of nicotine product use

The landscape of nicotine use in the United States (US) has continued to evolve, with electronic cigarette use (hereafter e-cigarette) becoming more evident in recent years. Patterns of dual nicotine use, or using combustible nicotine in conjunction with e-cigarettes, may increase dependence on nicotine, continued exposure to toxins, and corresponding health risks. One of the most prevalent health problems related to nicotine use is the experience of chronic pain. Past work has established a bidirectional relationship between nicotine use and pain, such that pain motivates nicotine use and nicotine use contributes to pain. However, no work has explored differences in negative mood and pain experience as a product of nicotine use type among adults with chronic low back pain. The current cross-sectional study examined whether dual cigarette/e-cigarette use was associated with greater anxiety, depression, and pain experience among a sample of adult nicotine users (cigarettes and/or e-cigarettes) with self-reported mild to severe chronic low back pain (N = 1034, 66.0% female, Mage= 44.47 years, SD = 11.63). Results indicated that, compared to exclusive combustible nicotine users, dual cigarette/e-cigarette users had statistically significantly higher anxiety, depression, and pain disability scores, beyond the effects of age, sex, education, and use of opioid medications for pain. No significant group differences emerged as a function of exclusive e-cigarette use. The current findings highlight that dual cigarette/e-cigarette use may serve to mark a subpopulation of persons with chronic low back pain who present more complicated clinical features that require comprehensive care.

Hypercapnia Reduces Perceived Heat Pain in Healthy Subjects

BACKGROUND

Danger signals modulate pain perception. Both amplification and attenuation of perceived pain are observed in healthy subjects exposed to danger signals, such as transient threats of an imminent electrical shock. However, exposure to danger signals in real life typically is not transient but constant over minutes to hours. Here, this was experimentally achieved by administering hypercapnic air (7.5% CO2). The primary objective was to investigate whether perceived heat pain would be differentially modulated during this intervention compared to regular air administration. The secondary objective assessed the potential differences of such a modulation with respect to heat intensity level.

METHODS

Thirty-eight participants (19 women) received two air mixtures (hypercapnic and regular air) for 13 min each, during which 18 (6 × 3) noxious heat stimuli of three different intensities were applied to the calf and rated on two scales (intensity and pleasantness/unpleasantness). Psychological and physiological states were compared between conditions using the body sensations questionnaire, self-assessment manikins, heart rate, and galvanic skin response. Statistical analyses were performed using Bayesian estimation testing.

RESULTS

Between-condition differences were statistically meaningful for all heat intensity levels, always showing reduced pain perception during hypercapnia compared to normocapnia. The magnitude of the observed hypoalgesia did not depend on heat intensity levels.

CONCLUSIONS

The presence of a continuous physiological danger signal results in hypoalgesia. Future studies need to determine whether the present results only hold for hypercapnia in healthy subjects or are generalisable to interactions between pain perception and continuous physiological danger signals in clinical pain populations.

SIGNIFICANCE STATEMENT

It was shown that hypercapnia leads to reduced perception of noxious heat stimuli. If confirmed by neural data in future studies this could help to better understand the interaction of pain perception and continuous physiological danger signals in clinical pain conditions, potentially allowing for improved treatment of affected individuals.

The Contribution of Sleep Quality and Psychological Factors to the Experience of Within-Day Pain Fluctuations Among Individuals With Temporomandibular Disorders

We assessed the impact of day-to-day sleep quality and psychological variables (catastrophizing, negative affect, and positive affect) to within-day pain fluctuations in 42 females with painful temporomandibular disorders (TMD) using electronic diaries. More specifically, we examined the contribution of these variables to the likelihood of experiencing pain exacerbations defined as 1) an increase of 20 points (or more) in pain intensity on a 0 to 100 visual analog scale from morning to evening, and/or 2) a transition from mild-to-moderate pain over the course of the day; and pain decreases defined as 3) a decrease of 20 points (or more) in pain intensity (visual analog scale) from morning to evening, and/or 4) a reduction from moderate-to-mild pain over the day. The results indicated significantly main effects of sleep on both pain exacerbation outcomes (both P's < .05), indicating that nights with better sleep quality were less likely to be followed by clinically meaningful pain exacerbations on the next day. The results also indicated that days characterized by higher levels of catastrophizing were associated with a greater likelihood of pain exacerbations on the same day (both P's < .05). Daily catastrophizing was the only variable significantly associated with within-day pain decrease indices (both P's < .05). None of the other variables were associated with these outcomes (all P's > .05). These results underscore the importance of addressing patients' sleep quality and psychological states in the management of painful TMD. PERSPECTIVE: These findings highlight the significance of sleep quality and pain catastrophizing in the experience of within-day pain fluctuations among individuals with TMD. Addressing these components through tailored interventions may help to alleviate the impact of pain fluctuations and enhance the overall well-being of TMD patients.

Heterogeneity in Temporal Dynamics of Pain and Affect Among Individuals With Chronic Back Pain and Associations With Risk for Future Opioid-Related Problems

Chronic low back pain (CLBP) is a biopsychosocial phenomenon involving complex relationships between pain and psychosocial factors. In preregistered analyses, we examined dynamic relationships between pain and negative affect among individuals with CLBP (N = 87). We found that increased negative affect was concurrently and prospectively associated with increased pain for individuals on average. However, there was significant and meaningful between-persons variability in these effects such that risk for future opioid-related problems was positively associated with the within-persons correlation between pain and negative affect (β = 0.290, 95% credible interval [CI] = [0.071, 0.485]), the degree to which pain predicted increased negative affect (β = 0.439, 95% CI = [0.044, 0.717]), and the autoregressive effect of negative affect over 4-hr lags (β = 0.255, 95% CI = [0.007, 0.478]). These results suggest that variability in within-persons symptom dynamics may help identify chronic pain patients who are at greater risk of opioid-related problems.

Physical Activity Moderates the Association Between Pain and Depressive Symptoms Among Persons with Multiple Sclerosis

OBJECTIVE

The present study examined physical activity as a possible moderator in the relationship between pain and depressive symptoms among persons with multiple sclerosis (PwMS).

METHOD

Fifty-three PwMS completed a comprehensive neuropsychological test battery and psychosocial questionnaires. Pain was operationalized as a composite of measures from the Brief Pain Inventory. Metabolic equivalents (METs) of energy expended during self-reported vigorous activity (VA), moderate activity (MA), and walking, as well as global physical activity which combined the three, were derived from the International Physical Activity Questionnaire-Short Form. Self-reported physical activity was measured using the Cognitive Health Questionnaire Exercise Scale. Regressions on depressive symptoms (Beck Depression Inventory-Fast Screen) examining both conceptualizations of physical activity, pain, and their interactions were explored.

RESULTS

Regression analyses revealed that interactions between pain and each measure of global physical activity were significant (p = .01). Simple effects tests revealed that pain only influenced depressive symptoms in PwMS with low global physical activity METs (p < .001) and low overall self-reported physical activity (p < .001). The separate interactions between pain and METs during self-reported VA, MA, and walking on depressive symptoms were not significant.

CONCLUSION

We found that global physical activity moderated the relationship between pain and depressive symptoms in MS. Specifically, pain influenced depressive symptoms in PwMS who engaged in less overall physical activity. These results highlight the importance of screening PwMS for pain and suggest that behavioral interventions aimed at increasing overall lifestyle physical activity may be useful in improving depressive outcomes in PwMS with pain.

Automating the analysis of facial emotion expression dynamics: A computational framework and application in psychotic disorders

Facial emotion expressions play a central role in interpersonal interactions; these displays are used to predict and influence the behavior of others. Despite their importance, quantifying and analyzing the dynamics of brief facial emotion expressions remains an understudied methodological challenge. Here, we present a method that leverages machine learning and network modeling to assess the dynamics of facial expressions. Using video recordings of clinical interviews, we demonstrate the utility of this approach in a sample of 96 people diagnosed with psychotic disorders and 116 never-psychotic adults. Participants diagnosed with schizophrenia tended to move from neutral expressions to uncommon expressions (e.g., fear, surprise), whereas participants diagnosed with other psychoses (e.g., mood disorders with psychosis) moved toward expressions of sadness. This method has broad applications to the study of normal and altered expressions of emotion and can be integrated with telemedicine to improve psychiatric assessment and treatment.

Predictors of increased affective symptoms and suicidal ideation during the COVID-19 pandemic: results from a large-scale study of 14 271 Thai adults

BACKGROUND

Increasing data suggest emergent affective symptoms during the COVID-19 pandemic.

OBJECTIVES

To study the impact of the COVID-19 pandemic on affective symptoms and suicidal ideation in Thai adults.

METHODS

The Collaborative Outcomes Study on Health and Functioning during Infection Times uses non-probability sampling (chain referring and voluntary response sampling) and stratified probability sampling to identify risk factors of mental health problems and potential treatment targets to improve mental health outcomes during pandemics.

FINDINGS

Analysing 14 271 adult survey participants across all four waves of the COVID-19 pandemic in Thailand, covering all 77 provinces from 1 June 2020 to 30 April 2022, affective symptoms and suicidality increased during COVID-19 pandemic. Affective symptoms were strongly predicted by pandemic (feelings of isolation, fear of COVID-19, loss of social support, financial loss, lack of protective devices) and non-pandemic (female sex, non-binary individuals, adverse childhood experiences (ACEs), negative life events, student status, multiple mental health and medical conditions, physical pain) risk factors. ACEs, prior mental health conditions and physical pain were the top three risk factors associated with both increased affective symptoms and suicidal ideation during the COVID-19 pandemic. Partial least squares analysis showed that ACEs were the most important risk factor as they impacted most pandemic and non-pandemic risk factors.

CLINICAL IMPLICATIONS

Rational policymaking during a pandemic should aim to identify the groups at highest risk (those with ACEs, psychiatric and medical disease, women, non-binary individuals) and implement both immediate and long-term strategies to mitigate the impact of ACEs, while effectively addressing associated psychiatric and medical conditions.

Soreness Reminds Me of Grief: Patients With Chronic Pain Show Less Differentiated Representations of Emotional Feelings and Bodily States

People experience similarities between emotional feelings and bodily states on a daily basis, but both the magnitude and pervasiveness of this experiential similarity vary across individuals. Inspired by previous findings that chronic pain (CP) is characterized by strengthened pain-affect coupling and reduced interoceptive accuracy, we conducted 2 cross-sectional studies to examine whether patients with CP would exhibit less differentiated perception and mental representation of emotional feelings and bodily states. In study 1 (N = 500), patients with CP and healthy controls (HCs) completed a self-report questionnaire that asked explicitly about the perceived similarity between 5 basic emotion categories and a series of bodily states. In study 2 (N = 73), a specially designed false memory test was administered to examine whether patients with CP would have reduced differentiation of concepts of negative emotion and somatic distress. We found that patients with CP perceived greater and more pervasive similarities between emotional feelings and bodily states, as indicated by higher questionnaire scores and denser, less specialized bipartite emotion-body networks, both associated with lower subjective interoceptive accuracy. Furthermore, patients with CP formed false memories of negative emotion words (eg, grief) more readily than HCs after memorizing somatic distress words (eg, soreness), as if they represented negative emotion and somatic distress as a single, enmeshed semantic category. Our findings extend previous literature by demonstrating reduced discrimination between emotional and bodily experiences in CP that is not restricted to pain-related emotional and sensory experiences and may be related to a fundamentally less differentiated interoception. PERSPECTIVES: This study shows that patients with chronic pain have a profoundly less differentiated perception and implicit conceptualization of emotional feelings and bodily states, which appears to be associated with altered interoception. These findings may provide new perspectives on why they often experience a stronger pain-affect coupling.

Implications for a mindfulness-enhanced positive affect induction: A brief commentary toward acute pain management

Over the past decade research has increased on dynamics between mindfulness, positive affect, and pain. While there have been studies examining the direct use of positive psychology for pain management, few have examined the use of a specific mindfulness-enhanced positive affect induction (i.e. a singular brief technique engendering mindfulness and strong positive affect) toward acute pain and pain flare management. This topical commentary discusses the need for such a technique toward bolstered gold-standard interventions, related studies, and possible future directions for acute and post-surgical pain management. Future research is encouraged to build from prior research on loving-kindness meditation and examine novel, brief mindfulness-enhanced positive affect inductions for acute pain management.

Evaluating the Effects of Rewards and Schedule Length on Response Rates to Ecological Momentary Assessment Surveys: Randomized Controlled Trials

BACKGROUND

Ecological momentary assessments (EMAs) are short, repeated surveys designed to collect information on experiences in real-time, real-life contexts. Embedding periodic bursts of EMAs within cohort studies enables the study of experiences on multiple timescales and could greatly enhance the accuracy of self-reported information. However, the burden on participants may be high and should be minimized to optimize EMA response rates.

OBJECTIVE

We aimed to evaluate the effects of study design features on EMA response rates.

METHODS

Embedded within an ongoing cohort study (Health@NUS), 3 bursts of EMAs were implemented over a 7-month period (April to October 2021). The response rate (percentage of completed EMA surveys from all sent EMA surveys; 30-42 individual EMA surveys sent/burst) for each burst was examined. Following a low response rate in burst 1, changes were made to the subsequent implementation strategy (SMS text message announcements instead of emails). In addition, 2 consecutive randomized controlled trials were conducted to evaluate the efficacy of 4 different reward structures (with fixed and bonus components) and 2 different schedule lengths (7 or 14 d) on changes to the EMA response rate. Analyses were conducted from 2021 to 2022 using ANOVA and analysis of covariance to examine group differences and mixed models to assess changes across all 3 bursts.

RESULTS

Participants (N=384) were university students (n=232, 60.4% female; mean age 23, SD 1.3 y) in Singapore. Changing the reward structure did not significantly change the response rate (F3,380=1.75; P=.16). Changing the schedule length did significantly change the response rate (F1,382=6.23; P=.01); the response rate was higher for the longer schedule (14 d; mean 48.34%, SD 33.17%) than the shorter schedule (7 d; mean 38.52%, SD 33.44%). The average response rate was higher in burst 2 and burst 3 (mean 50.56, SD 33.61 and mean 48.34, SD 33.17, respectively) than in burst 1 (mean 25.78, SD 30.12), and the difference was statistically significant (F2,766=93.83; P<.001).

CONCLUSIONS

Small changes to the implementation strategy (SMS text messages instead of emails) may have contributed to increasing the response rate over time. Changing the available rewards did not lead to a significant difference in the response rate, whereas changing the schedule length did lead to a significant difference in the response rate. Our study provides novel insights on how to implement EMA surveys in ongoing cohort studies. This knowledge is essential for conducting high-quality studies using EMA surveys.

TRIAL REGISTRATION

ClinicalTrials.gov NCT05154227; https://clinicaltrials.gov/ct2/show/NCT05154227.

Bidirectional Links of Daily Sleep Quality and Duration With Pain and Self-rated Health in Older Adults' Daily Lives

BACKGROUND

Sleep and health perceptions, such as self-ratings of pain and health are closely linked. However, the temporal ordering of such associations is not well understood, and it remains unclear whether sleep quality and sleep duration show similar or differential associations with health perceptions.

METHODS

We used ecological momentary assessment data from 123 young-old (66-69 years, 47% women) and 47 old-old adults (84-90 years, 60% women). Across 7 consecutive days, participants reported their sleep quality and sleep duration each morning and rated their momentary pain and health 6 times per day. We applied dynamic structural equation models to examine bidirectional links of morning reports of sleep quality and duration with daily levels of self-rated pain and health.

RESULTS

In line with the hypotheses, results showed that when participants reported better sleep quality than what is typical for them, they reported less pain and better self-rated health on the day that followed. Longer sleep duration was not linked with subsequent pain or self-rated health. On days when people rated their health as better than usual, they reported better sleep quality but not longer sleep duration the following night. These associations were not moderated by age, gender, or chronic pain.

CONCLUSION

Findings suggest that in old age, sleep quality is more relevant for health perceptions than sleep duration. Associations between sleep quality and self-rated health seem to be bidirectional; daily pain was linked to prior but not subsequent sleep quality.

Establishing the Reliability, Validity, and Prognostic Utility of the Momentary Pain Catastrophizing Scale for Use in Ecological Momentary Assessment Research

Despite the marked increase in ecological momentary assessment research, few reliable and valid measures of momentary experiences have been established. The goal of this preregistered study was to establish the reliability, validity, and prognostic utility of the momentary Pain Catastrophizing Scale (mPCS), a 3-item measure developed to assess situational pain catastrophizing. Participants in 2 studies of postsurgical pain outcomes completed the mPCS 3 to 5 times per day prior to surgery (N = 494, T = 20,271 total assessments). The mPCS showed good psychometric properties, including multilevel reliability and factor invariance across time. Participant-level average mPCS was strongly positively correlated with dispositional pain catastrophizing as assessed by the Pain Catastrophizing Scale (r = .55 and .69 in study 1 and study 2, respectively). To establish prognostic utility, we then examined whether the mPCS improved prediction of postsurgical pain outcomes above and beyond one-time assessment of dispositional pain catastrophizing. Indeed, greater variability in momentary pain catastrophizing prior to surgery was uniquely associated with increased pain immediately after surgery (b = .58, P = .005), after controlling for preoperative pain levels and dispositional pain catastrophizing. Greater average mPCS score prior to surgery was also uniquely associated with lesser day-to-day improvement in postsurgical pain (b = .01, P = .003), whereas dispositional pain catastrophizing was not (b = -.007, P = .099). These results show that the mPCS is a reliable and valid tool for ecological momentary assessment research and highlight its potential utility over and above retrospective measures of pain catastrophizing. PERSPECTIVE: This article presents the psychometric properties and prognostic utility of a new measure to assess momentary pain catastrophizing. This brief, 3-item measure will allow researchers and clinicians to assess fluctuations in pain catastrophizing during individuals' daily lives, as well as dynamic relationships between catastrophizing, pain, and related factors.

Chronic pain, chronic stress and substance use: overlapping mechanisms and implications

Chronic pain is among the most common reasons adults in the U.S. seek medical care. Despite chronic pain's substantial impact on individuals' physical, emotional, and financial wellness, the biologic underpinnings of chronic pain remain incompletely understood. Such deleterious impact on an individuals' wellness is also manifested in the substantial co-occurrence of chronic stress with chronic pain. However, whether chronic stress and adversity and related alcohol and substance misuse increases risk of developing chronic pain, and, if so, what the overlapping psychobiological processes are, is not well understood. Individuals suffering with chronic pain find alleviation through prescription opioids as well as non-prescribed cannabis, alcohol, and other drugs to control pain, and use of these substances have grown significantly. Substance misuse also increases experience of chronic stress. Thus, given the evidence showing a strong correlation between chronic stress and chronic pain, we aim to review and identify overlapping factors and processes. We first explore the predisposing factors and psychologic features common to both conditions. This is followed by examining the overlapping neural circuitry of pain and stress in order to trace a common pathophysiologic processes for the development of chronic pain and its link to substance use. Based on the previous literature and our own findings, we propose a critical role for ventromedial prefrontal cortex dysfunction, an overlapping brain area associated with the regulation of both pain and stress that is also affected by substance use, as key in the risk of developing chronic pain. Finally, we identify the need for future research in exploring the role of medial prefrontal circuits in chronic pain pathology. Critically, in order to alleviate the enormous burden of chronic pain without exacerbating the co-occurring substance misuse crisis, we emphasize the need to find better approaches to treat and prevent chronic pain.

Prosocial behaviour helps to ease physical pain: Longitudinal evidence from Britain

OBJECTIVE

Prior studies suggest that prosocial behaviour can lead to better mental and physical health. Yet little is known about whether engaging in prosocial behaviour contributes to reducing physical pain. The objective of this study is to investigate longitudinal associations of two prosocial behaviours, donating money to charity and/or volunteering time to an organisation, with pain.

METHODS

Data are from the United Kingdom Household Longitudinal Survey (UKHLS, approximate N = 48,000 individuals). Both prosocial behaviours were assessed in 2011 and pain was assessed annually through 2020, according to the extent to which it interfered with respondents' ability to do work. Using a prospective longitudinal study design, linear mixed models examined associations of each prosocial behaviour separately and both combined on pain interference across 10 years of follow-up adjusting for a broad range of covariates including demographics, initial health status, and depression.

RESULTS

People who did versus did not donate or volunteer reported lower pain interference over 10 years of follow-up (donating b = -0.059, p < 0.001; volunteering b = -0.086, p < 0.001). Individuals who donated more versus less money reported lower pain interference although volunteering more hours was not associated with lower pain interference. Finally, findings suggested that engaging in both donating and volunteering versus neither was associated with lower pain interference over follow-up.

CONCLUSION

There is a longitudinal association between donating money to charity and/or volunteering time to an organisation with pain interference with work. Understanding factors that help to reduce pain is relevant for the design of public health policies.