The association of sleep and pain: an update and a path forward

Chronotype, Sleep Characteristics, and Musculoskeletal Disorders Among Hospital Nurses

Work-related musculoskeletal disorders (WMSDs) persist as the leading occupational injury, accounting for nearly half of nurses' total occupational injuries. Musculoskeletal pain is a known cause of sleep disruption, and individuals with WMSDs that interfere with sleep often report more pain. Evening chronotype has been associated with poor sleep among nurses. However, the associations among chronotype, sleep, and WMSDs are still unclear, and were explored in the present study. A cross-sectional survey was administered to 397 nurses, with 47.4% reporting WMSDs. Robust Poisson regression modeling suggested that evening type (PR = 1.32, p < .05), prolonged sleep onset latency (PR = 1.37, p < .05), and using sleep-promoting substances (PR = 1.35, p < .01) were associated with increased risk of WMSDs among nurses, after adjusting for shift work, regular exercise, body mass index, and other covariates. This study suggests that well-designed evidence-based nonpharmacological interventions to improve sleep may reduce the risk of WMSDs among nurses.

Disentangling the Sleep-Pain Relationship in Pediatric Chronic Pain: The Mediating Role of Internalizing Mental Health Symptoms

Background

Pediatric chronic pain often emerges in adolescence and cooccurs with internalizing mental health issues and sleep impairments. Emerging evidence suggests that sleep problems may precede the onset of chronic pain as well as anxiety and depression. Studies conducted in pediatric populations with pain-related chronic illnesses suggest that internalizing mental health symptoms may mediate the sleep-pain relationship; however, this has not been examined in youth with primary pain disorders.

Objective

To examine whether anxiety and depressive symptoms mediated relationships between sleep quality and pain outcomes among youth with chronic pain.

Methods

Participants included 147 youth (66.7% female) aged 8-18 years who were referred to a tertiary-level chronic pain program. At intake, the youth completed psychometrically sound measures of sleep quality, pain intensity, pain interference, and anxiety and depressive symptoms.

Results

As hypothesized, poor sleep quality was associated with increased pain intensity and pain interference, and anxiety and depressive symptoms mediated these sleep-pain relationships.

Discussion

For youth with chronic pain, poor sleep quality may worsen pain through alterations in mood and anxiety; however, prospective research using objective measures is needed. Future research should examine whether targeting sleep and internalizing mental health symptoms in treatments improve pain outcomes in these youth.

Are Sleep Problems a Risk Factor for the Onset of Musculoskeletal Pain in Children and Adolescents? A Systematic Review

Study Objectives

Musculoskeletal pain is a major burden on the society. Adults with sleep problems are at higher risk of musculoskeletal pain onset, but there is no evidence for this relationship in children and adolescents. This study aimed to systematically review prospective studies on the risk of musculoskeletal pain onset in children and adolescents with sleep problems.

Methods

Five databases (MEDLINE, PsycINFO, AMED, EMBASE, and HMIC) were systematically searched to identify prospective studies that investigated if children and adolescents (aged 6-19 years) with sleep problems are at higher risk of musculoskeletal pain onset. Included studies were assessed for study quality and a best evidence synthesis was carried out on extracted data.

Results

Thirteen prospective studies were identified. Overall, evidence indicates that sleep problems (quality, quantity, and day time tiredness) are not risk factors for musculoskeletal pain onset. Further analysis on specific body regions shows strong evidence that sleep problems are a risk factor for neck pain onset (only in girls) and that sleep problems are not a risk factor for the onset of widespread pain.

Conclusions

Overall, sleep problems are not a risk factor for musculoskeletal pain onset in children and adolescents. Increased risk was found for some specific body regions and subgroups, but the evidence base was less strong and generally inconsistent. This review found a lack of quality in research methodology compared to research in adults, and further research with improved methodology is required.

Sleep Disturbance Mediates the Association of Post-Traumatic Stress Disorder Symptoms and Pain in Patients With Cancer

BACKGROUND

Sleep disturbance is a common complaint of patients with cancer and is well established in both pain conditions and post-traumatic stress disorder (PTSD). An estimated one-third of patients with cancer develop symptoms of PTSD at some point in their treatment. However, few studies have evaluated the contributions of PTSD and sleep disturbance to pain processes in cancer populations. The current study used mediation models to test the hypothesis that sleep disturbance would mediate the relationships between PTSD symptoms and pain intensity and PTSD symptoms and pain interference in a sample of patients with cancer.

METHODS

A cross-sectional, retrospective chart review was conducted of the electronic medical records of 85 adult patients with cancer (89.4% female; 59% white; 42% metastatic) who sought individual psychosocial support services at our institution.

RESULTS

Post-traumatic stress disorder symptoms, sleep disturbance, pain intensity, and pain interference were all positively correlated ( P < .01). Clinical levels of PTSD symptoms were reported by 30% to 60% of the sample. Even after controlling for metastatic disease, race, and cancer type, sleep disturbance mediated the relationships between PTSD symptoms and pain intensity ( B = 0.27; 95% CI: 0.10-0.44) and PTSD symptoms and pain-related interference ( B = 0.58; 95% CI: 0.28-0.87).

CONCLUSIONS

The relationships among PTSD symptoms, pain intensity, and pain interference could be explained by co-occurring sleep disturbance. Given the high frequency of PTSD symptoms among patients with cancer and PTSD's known links to sleep problems and pain, clinicians should be attentive to the role that traumatogenic processes may play in eliciting sleep and pain-related complaints among patients with cancer.

Anxiety and Insomnia in Young and Middle-Aged Adult Hip Pain Patients With and Without Femoroacetabular Impingement and Developmental Hip Dysplasia

BACKGROUND

In young and middle-aged adults with and without hip deformity, hip pain receives treatment focused primarily related to hip structure. Because this hip pain may be chronic, these patients develop other coexisting, modifiable disorders related to pain that may go undiagnosed in this young and active population, including insomnia and anxiety.

OBJECTIVE

The objective of this study was to compare assessments of insomnia and anxiety in young and middle-aged adults presenting with hip pain with no greater than minimal osteoarthritis (OA) compared to asymptomatic healthy controls. Comparisons between types of hip deformity and no hip deformity in hip pain patients were performed to assess whether patients with specific hip deformities were likely to have insomnia or anxiety as a cofounding disorder to their hip pain.

DESIGN

Prospective case series with control comparison.

SETTING

Two tertiary university physiatry outpatient clinics.

PARTICIPANTS

A total of 50 hip pain patients aged 18-40 years and 50 gender- and age-matched healthy controls.

METHODS

Patients were enrolled if 2 provocative hip tests were found on physical examination and hip radiographs had no or minimal OA. Radiographic hip deformity measurements were completed by an independent examiner. Comparisons of insomnia and anxiety were completed between 50 hip pain patients and 50 controls and between patients with different types of hip deformity.

MAIN OUTCOME MEASURES

Insomnia Severity Index (ISI) and Pain Anxiety Symptoms Scale (PASS).

RESULTS

A total of 50 hip pain patients (11 male and 39 female) with mean age of 31.2 ± 8.31 years enrolled. Hip pain patients slept significantly less (P = .001) per night than controls. Patients experienced significantly greater insomnia (P = .0001) and anxiety (P = .0001) compared to controls. No differences were found in insomnia and anxiety scores between hip pain patients with and without hip deformity or between different types of hip deformity.

CONCLUSION

Hip pain patients with radiographs demonstrating minimal to no hip arthritis with and without hip deformity experience significant cofounding yet modifiable disorders of sleep and anxiety. If recognized early in presentation, treatment of insomnia and anxiety ultimately will improve outcomes for hip patients treated either conservatively or surgically for their hip disorder.

LEVEL OF EVIDENCE

II.

Mid-Treatment Sleep Duration Predicts Clinically Significant Knee Osteoarthritis Pain reduction at 6 months: Effects From a Behavioral Sleep Medicine Clinical Trial

Study Objectives

To determine the relative influence of sleep continuity (sleep efficiency, sleep onset latency, total sleep time [TST], and wake after sleep onset) on clinical pain outcomes within a trial of cognitive behavioral therapy for insomnia (CBT-I) for patients with comorbid knee osteoarthritis and insomnia.

Methods

Secondary analyses were performed on data from 74 patients with comorbid insomnia and knee osteoarthritis who completed a randomized clinical trial of 8-session multicomponent CBT-I versus an active behavioral desensitization control condition (BD), including a 6-month follow-up assessment. Data used herein include daily diaries of sleep parameters, actigraphy data, and self-report questionnaires administered at specific time points.

Results

Patients who reported at least 30% improvement in self-reported pain from baseline to 6-month follow-up were considered responders (N = 31). Pain responders and nonresponders did not differ significantly at baseline across any sleep continuity measures. At mid-treatment, only TST predicted pain response via t tests and logistic regression, whereas other measures of sleep continuity were nonsignificant. Recursive partitioning analyses identified a minimum cut-point of 382 min of TST achieved at mid-treatment in order to best predict pain improvements 6-month posttreatment. Actigraphy results followed the same pattern as daily diary-based results.

Conclusions

Clinically significant pain reductions in response to both CBT-I and BD were optimally predicted by achieving approximately 6.5 hr sleep duration by mid-treatment. Thus, tailoring interventions to increase TST early in treatment may be an effective strategy to promote long-term pain reductions. More comprehensive research on components of behavioral sleep medicine treatments that contribute to pain response is warranted.

Interpreting the Effectiveness of Opioids and Pregabalin for Pain Severity, Pain Interference, and Fatigue in Fibromyalgia Patients

OBJECTIVE

To evaluate the effectiveness of opioids and/or pregabalin on patient-reported outcomes among fibromyalgia (FM) patients based on levels of improvement.

METHODS

A total of 1,421 FM patients were identified, with 3,082 observational periods of opioids with or without pregabalin use between April 2008 and February 2015. Patients were categorized by opioids, and pregabalin with and without opioids; opioids were designated by morphine equivalent dose (MED) of ≤ 20 (low MED), > 20 to < 100 (moderate MED), ≥ 100 (high MED), and pregabalin doses of ≤ 150 mg, 151 to 300 mg, and 301 to 450 mg. Proportions of patients meeting clinically relevant thresholds of ≥ 30% and ≥ 50% improvement for pain interference (ability to enjoy life; activity; mood; relationships; sleep), pain severity, and fatigue were compared among treatments, and area under the curve (AUC) for improvement and worsening of effects was determined, enabling ranking of treatments. Further analysis compared pregabalin doses.

RESULTS

Pregabalin without opioids resulted in the highest proportions of patients with ≥ 30% improvement on all pain items and pain interference with "ability to enjoy life," "activity" "mood," and "sleep." For the ≥ 50% threshold, pregabalin alone was highest for all pain interference items and for "average pain" and "worst pain." Pregabalin was consistently lowest across thresholds for fatigue, but showed better results combined with moderate MED opioids. Pregabalin doses recommended for treatment of FM (151 to 450 mg) generally resulted in the highest proportion of patients achieving thresholds relative to opioids. The AUC results were consistent with thresholds; pregabalin without opioids resulted in the greatest benefits with regard to improvement, with the highest ranking for overall improvement and overall effects.

CONCLUSION

Pregabalin without opioids provided the most favorable outcomes overall based on ≥ 30% and ≥ 50% improvement thresholds and AUC, with support for moderate MED opioids + pregabalin in patients suffering from fatigue. While most patients took less than recommended pregabalin doses, higher doses may lead to improved outcomes.

Association of insomnia severity with well-being, quality of life and health care costs: A cross-sectional study in older adults with chronic pain (PainS65+)

BACKGROUND

Insomnia is one of the most common complaints in chronic pain. This study aimed to evaluate the association of insomnia with well-being, quality of life and health care costs.

METHODS

The sample included 2790 older individuals (median age = 76; interquartile range [IQR] = 70-82) with chronic pain. The participants completed a postal survey assessing basic demographic data, pain intensity and frequency, height, weight, comorbidities, general well-being, quality of life and the insomnia severity index (ISI). Data on health care costs were calculated as costs per year (€ prices) and measured in terms of outpatient and inpatient care, pain drugs, total drugs and total health care costs.

RESULTS

The overall fraction of clinical insomnia was 24.6% (moderate clinical insomnia: 21.9% [95% CI: 18.8-23.3]; severe clinical insomnia: 2.7% [95% CI: 1.6-3.2]). Persons who reported clinical insomnia were more likely to experience pain more frequently with higher pain intensity compared to those reported no clinically significant insomnia. Mean total health care costs were € 8469 (95% CI: €4029-€14,271) for persons with severe insomnia compared with € 4345 (95% CI: €4033-€4694) for persons with no clinically significant insomnia. An association between severe insomnia, well-being, quality of life, outpatient care, total drugs costs and total health care costs remained after controlling for age, sex, pain intensity, frequency, body mass index and comorbidities using linear regression models.

CONCLUSIONS

Our results determine an independent association of insomnia with low health-related quality of life and increased health care costs in older adults with chronic pain.

SIGNIFICANCE

The concurrence and the severity of insomnia among older adults with chronic pain were associated with decreased well-being and quality of life, and increased health care costs to society.

[Study of chronic pain and its associated risk factors among Japanese industry workers: the Quality of Working Life Influenced by Chronic pain (QWLIC) study]

OBJECTIVES

This study was performed to identify the prevalence, influence, and risk factors associated with chronic pain among Japanese industry workers.

METHODS

We investigated 2,544 participants working at a manufacturing company A, a manufacturing company B, and 16 branch shops of a retail chain company C. The participants responded to self-administered questionnaires related to pain. Furthermore, data obtained from the lifestyle interview sheet of an annual health screening examination and those obtained from the questionnaires were merged. We analyzed the association between lifestyles, psychosocial factors, and chronic pain. Age- and sex-adjusted odds ratios were calculated with a 95% confidence interval using the logistic regression model.

RESULTS

Of 2,544 participants, 1,914 (1,224 men and 690 women) completed the questionnaire, and the response rate was 75.2%. The prevalence of chronic pain over 3 months was 42.7% and that of chronic pain with work disability was 11.3%. A higher proportion of obesity, smoking habit, insomnia, psychological stress, depressive state, workaholic nature, low social support from supervisors and coworkers, high job demand, low job control, and job dissatisfaction was observed in workers with chronic pain than in workers without pain.

CONCLUSIONS

Several risk factors of chronic pain in Japanese industry workers were found. Obesity, smoking habits, sleep disorders, workplace environment, and mental state should be taken into account as risk factors associated with chronic pain issues and general occupational health.

Modulation of Glycine-Mediated Spinal Neurotransmission for the Treatment of Chronic Pain

Chronic pain constitutes a significant and expanding worldwide health crisis. Currently available analgesics poorly serve individuals suffering from chronic pain, and new therapeutic agents that are more effective, safer, and devoid of abuse liabilities are desperately needed. Among the myriad of cellular and molecular processes contributing to chronic pain, spinal disinhibition of pain signaling to higher cortical centers plays a critical role. Accumulating evidence shows that glycinergic inhibitory neurotransmission in the spinal cord dorsal horn gates nociceptive signaling, is essential in maintaining physiological pain sensitivity, and is diminished in pathological pain states. Thus, it is hypothesized that agents capable of enhancing glycinergic tone within the dorsal horn could obtund nociceptor signaling to the brain and serve as analgesics for persistent pain. This Perspective highlights the potential that pharmacotherapies capable of increasing inhibitory spinal glycinergic neurotransmission hold in providing new and transformative analgesic therapies for the treatment of chronic pain.

Does physical activity buffer insomnia due to back and neck pain?

INTRODUCTION

Musculoskeletal pain is highly prevalent and a burden to society, recurrent and persistent low back pain (LBP) and neck pain (NP) being the most common conditions. They are associated with other poor health outcomes such as sleep problems. Physical activity (PA) prevents LBP and NP, but the direct effect on sleep is unclear. This study explored the effect of pain on insomnia, and examined if adherence to moderate-to-high intensity levels of PA influenced this relationship.

METHODS

In this prospective observational study, 1821 workers were followed over 3 years. Data included self-rated measures of LBP and NP, insomnia and level and amount of PA. Pain variables were used in a "risk profile" for future sick-listing, insomnia was categorized into those with and without such problems, and adherence to PA was defined as reporting moderate-to-high levels in two consecutive years. In Poisson regression models, individuals with pain risk profiles were analysed according to PA adherence for the outcome insomnia. Repeated measurements allowed control for prior pain.

RESULTS

In this mainly male working population, individuals with a risk profile for LBP and NP had a significant increased risk (RR = 1.5) of developing insomnia one year later when not adhering to moderate-to-high levels of PA. Among those not reporting prior pain, the risk was even larger (RR = 2.5). Generalizability may be restricted to relatively healthy males. The individuals who reported a pain risk profile two consecutive years did not get the buffer effect from adhering to moderate-to-high levels of PA in terms of developing insomnia.

Sleep Quality, Affect, Pain, and Disability in Children With Chronic Pain: Is Affect a Mediator or Moderator?

Sleep problems have been identified as a potential antecedent of chronic pain and pain-related disability in pediatric populations. In adult studies, affect has been implicated in these relationships. This study sought to better understand the relationships between sleep quality, negative and positive affect, and pain and functioning in children with chronic pain. Participants included 213 children and adolescents (aged 7-17 years) presenting to a tertiary pain clinic with chronic pain. Children completed questionnaires measuring sleep quality, positive and negative affect, pain intensity, and functional disability. Results indicated that 74% of children reported disordered sleeping and that poor sleep quality was significantly associated with increased pain, disability, negative affect, and decreased positive affect. Our hypotheses were partially supported, with negative affect (but not positive affect) mediating the relationship between poor sleep and increased pain; and positive as well as negative affect mediating the relationship between poor sleep and increased functional disability. There was no evidence for affect as a moderator. This study adds to the growing literature demonstrating the effect of poor sleep quality on children's pain and functioning, highlighting the need to develop further longitudinal research to confirm the causal roles of these variables.

PERSPECTIVE

This article examines the relationship between poor sleep quality, affect (negative as well as positive), pain, and disability in children with chronic pain. The findings have the potential to better understand the processes involved in how poor sleep may lead to increased pain and pain-related disability.

Predicting treatment outcomes of pain patients attending tertiary multidisciplinary pain treatment centers: A pain trajectory approach

Background: Though multidisciplinary pain treatment (MPT) is considered the gold standard for managing chronic pain, it is unclear which patients benefit most from this high-cost treatment approach.

Aims: The goals were to identify subgroups of patients sharing similar pain severity trajectories over time and predictors of MPT responsiveness.

Methods: Participants were 1894 patients (mean age = 53.18 years [SD = 14.0]; female = 60.3%) enrolled in the Quebec Pain Registry with moderate to severe baseline pain severity. Patients completed validated questionnaires on pain and related constructs before initiating treatment and 6, 12, and 24 months later.

Results: Trajectory analyses of pain severity (intensity and interference) showed that a three-class model best fit the data. Two of the trajectories, which included 24.5% of patients, showed significant improvement in pain severity levels over time (improvers). Compared to patients in the nonimproving trajectory (non-improvers), improvers were younger and more likely to suffer from neuropathic pain and had pain of shorter duration, lower worst pain intensity, lower sleep disturbances and depression scores at baseline, a lower tendency to catastrophize, and better physical health–related quality of life (QOL). This predictive model had a specificity of 96.2% and a sensitivity of 23.6%.

Conclusions: Only a minority of patients exhibited an improvement in their pain severity with MPT. Several patients’ characteristics were significantly associated with pain trajectory membership. Early identification of nonimprovers, through examination of baseline characteristics and rates of change in pain scores, can provide valuable information about prognosis and open the doors for evaluation of different cost-effective treatment approaches.

Abbreviations: CP = chronic pain; MPT = multidisciplinary pain treatment; QPR = Quebec Pain Registry; QOL = quality of life.

Temporal daily associations among sleep and pain in treatment-seeking youth with acute musculoskeletal pain

Sleep is an important health risk factor. In the context of pediatric chronic pain, sleep is often impaired and temporal daily associations link sleep deficiency to subsequent increased pain. It is unknown whether similar temporal relationships exist for youth with acute pain. Thus, we characterized sleep in youth with acute musculoskeletal (MSK) pain to examine daily sleep-pain associations. Participants were 67 youth (10-17 years) with acute MSK pain (<1 month duration). Youth underwent eight nights of actigraphic sleep monitoring and completed twice daily pain diaries. Generalized linear models tested nighttime sleep as a predictor of morning pain, and evening pain as a predictor of nighttime sleep. Shorter sleep duration and poorer sleep quality predicted higher morning pain intensity. However, evening pain did not predict nighttime sleep, suggesting the strongest temporal association is in the direction of sleep deficiency impacting next-day pain, as has been found in prior research in youth with chronic pain.

The interfaces between vitamin D, sleep and pain

The role of vitamin D in osteomineral metabolism is well known. Several studies have suggested its action on different biological mechanisms, such as nociceptive sensitivity and sleep-wake cycle modulation. Sleep is an important biological process regulated by different regions of the central nervous system, mainly the hypothalamus, in combination with several neurotransmitters. Pain, which can be classified as nociceptive, neuropathic and psychological, is regulated by both the central and peripheral nervous systems. In the peripheral nervous system, the immune system participates in the inflammatory process that contributes to hyperalgesia. Sleep deprivation is an important condition related to hyperalgesia, and recently it has also been associated with vitamin D. Poor sleep efficiency and sleep disorders have been shown to have an important role in hyperalgesia, and be associated with different vitamin D values. Vitamin D has been inversely correlated with painful manifestations, such as fibromyalgia and rheumatic diseases. Studies have demonstrated a possible action of vitamin D in the regulatory mechanisms of both sleep and pain. The supplementation of vitamin D associated with good sleep hygiene may have a therapeutic role, not only in sleep disorders but also in the prevention and treatment of chronic pain conditions.

Chronic pain in high school students is associated with physical activity and sleeping hours but not with screen time

Background Existing studies on the association between physical activity (PA), screen based time and sleeping show conflicting results. Objective This study investigates the association between chronic pain at different body regions and self-reported PA, screen based time and sleeping hours in high school students. Subjects A total of 969 students aged 13-19 years old. Methods Participants completed a questionnaire on chronic pain, time spent in moderate and vigorous PA, screen based time watching televivsion (TV)/digital versatile discs (DVD), playing, using mobile phones and computers and sleeping hours. Univariate and multivariate associations between pain and PA, screen based time and sleeping hours were investigated. Results In the univariate model time spent in moderate and vigorous PA, in screen based activities and sleeping were associated with pain in at least one body site. In the multivariate model, screen based activities were not associated with pain; sleeping 7 h or less and increased time in moderate PA were associated with pain at almost all body sites [odds ratio (OR) between 2.69-3.66 and 1.06-1.10, respectively]. Conclusion Time spent in PA and sleeping increased the risk of chronic pain in almost all body regions and might confound the association between screen based time and pain.

Sleep and somatic complaints in university students

BACKGROUND

Sleep problems are common among university students. Poor sleep is associated with impaired daily functioning, increased risk of psychiatric symptoms, and somatic complaints such as pain. Previous results suggest that poor sleep exacerbates pain, which in turn negatively affects sleep. The purpose of the present study was to determine prevalence rates, comorbidity, and role of depression as a factor of moderating the relationship between sleep and physical complaints in German university students.

SAMPLES AND METHODS

In total, 2443 German university students (65% women) completed a web survey. Self-report measures included the Pittsburg Sleep Quality Index, three modules of the Patient Health Questionnaire, and a questionnaire on the functional somatic syndromes (FSSs).

RESULTS

More than one-third (36.9%) reported poor sleep as assessed by the Pittsburgh Sleep Quality Index. Somatoform syndrome was identified in 23.5%, and the prevalence of any FSS was 12.8%. Self-reported sleep quality, sleep onset latency, sleep disturbances, use of sleep medications, and daytime dysfunctioning were significant predictors of somatoform syndrome, whereas sleep efficiency and sleep duration influenced somatic complaints indirectly. Moderate correlations were found between stress, anxiety, somatoform syndrome, depression, and overall sleep quality. The effect of somatic complaints on sleep quality was associated with the severity of depression. Anxiety shows direct effects on somatization and depression but only indirect associations with sleep quality.

Pain, pain intensity and pain disability in high school students are differently associated with physical activity, screening hours and sleep

Background

Studies exploring the association between physical activity, screen time and sleep and pain usually focus on a limited number of painful body sites. Nevertheless, pain at different body sites is likely to be of different nature. Therefore, this study aims to explore and compare the association between time spent in self-reported physical activity, in screen based activities and sleeping and i) pain presence in the last 7-days for 9 different body sites; ii) pain intensity at 9 different body sites and iii) global disability.

Methods

Nine hundred sixty nine students completed a questionnaire on pain, time spent in moderate and vigorous physical activity, screen based time watching TV/DVD, playing, using mobile phones and computers and sleeping hours. Univariate and multivariate associations between pain presence, pain intensity and disability and physical activity, screen based time and sleeping hours were investigated.

Results

Pain presence: sleeping remained in the multivariable model for the neck, mid back, wrists, knees and ankles/feet (OR 1.17 to 2.11); moderate physical activity remained in the multivariate model for the neck, shoulders, wrists, hips and ankles/feet (OR 1.06 to 1.08); vigorous physical activity remained in the multivariate model for mid back, knees and ankles/feet (OR 1.05 to 1.09) and screen time remained in the multivariate model for the low back (OR = 2.34. Pain intensity: screen time and moderate physical activity remained in the multivariable model for pain intensity at the neck, mid back, low back, shoulder, knees and ankles/feet (Rp² 0.02 to 0.04) and at the wrists (Rp² = 0.04), respectively. Disability showed no association with sleeping, screen time or physical activity.

Conclusions

This study suggests both similarities and differences in the patterns of association between time spent in physical activity, sleeping and in screen based activities and pain presence at 8 different body sites. In addition, they also suggest that the factors associated with the presence of pain, pain intensity and pain associated disability are different.

Decreased alertness due to sleep loss increases pain sensitivity in mice

Extended daytime and nighttime activities are major contributors to the growing sleep deficiency epidemic, as is the high prevalence of sleep disorders like insomnia. The consequences of chronic insufficient sleep for health remain uncertain. Sleep quality and duration predict presence of pain the next day in healthy subjects, suggesting that sleep disturbances alone may worsen pain, and experimental sleep deprivation in humans supports this claim. We demonstrate that sleep loss, but not sleep fragmentation, in healthy mice increases sensitivity to noxious stimuli (referred to as 'pain') without general sensory hyper-responsiveness. Moderate daily repeated sleep loss leads to a progressive accumulation of sleep debt and also to exaggerated pain responses, both of which are rescued after restoration of normal sleep. Caffeine and modafinil, two wake-promoting agents that have no analgesic activity in rested mice, immediately normalize pain sensitivity in sleep-deprived animals, without affecting sleep debt. The reversibility of mild sleep-loss-induced pain by wake-promoting agents reveals an unsuspected role for alertness in setting pain sensitivity. Clinically, insufficient or poor-quality sleep may worsen pain and this enhanced pain may be reduced not by analgesics, whose effectiveness is reduced, but by increasing alertness or providing better sleep.

Racial/ethnic differences in sleep quality among older adults with osteoarthritis

OBJECTIVE

To examine racial/ethnic differences in sleep quality and the pain-sleep association among older adults with osteoarthritis of the knee.

DESIGN

Baseline interview followed by a 7-day microlongitudinal study using accelerometry and self-reports.

SETTING

Participants were community residents in western Alabama and Long Island, NY.

PARTICIPANTS

Ninety-six African Americans (AAs) and 128 non-Hispanic whites (NHWs) with physician-diagnosed knee osteoarthritis, recruited from a variety of clinical and community settings.

MEASUREMENTS

Self-reports yielded demographics, body mass index, physical health problems, and depressive symptoms. Sleep quality was measured for 3 to 7 nights using wrist-worn accelerometers; pain was self-reported daily over the same period.

RESULTS

With demographics and health controlled, AAs displayed poorer sleep efficiency, greater time awake after sleep onset and sleep fragmentation, and marginally more awakenings during the night, but no differences in total sleep time. AAs also showed greater night-to-night variability in number of awakenings and sleep fragmentation, and marginally greater variability in total sleep time and sleep efficiency. Sleep quality was not associated with pain either the day before sleep or the day after. Average daily pain interacted with race, whereas AAs displayed no effect of pain on sleep efficiency, NHWs exhibited better sleep efficiency at higher levels of average pain.

CONCLUSIONS

These data corroborate previous studies documenting poorer sleep among AAs vs NHWs. The findings of greater night-to-night variability in sleep among AAs, as well as a negative association of pain with sleep quality among NHWs, are unique. Further study is needed to elucidate these findings.

Impact of insomnia on pain in postmenopausal women

BACKGROUND

Sleep disturbances and pain are assumed to be reciprocally linked. Insomnia and pain are central symptoms of the postmenopausal period and are closely related. Insomnia affects quality of life, increases pain sensitivity, the risk of pain-related disability, and other health problems.

OBJECTIVE

To investigate whether insomnia influences aspects of pain (pain intensity and the effect of pain on daily function) in postmenopausal women, and to evaluate the objective sleep pattern of insomniacs with pain.

METHODS

Fifty-seven women completed questionnaires about insomnia, climacteric symptoms, and pain. Polysomnography data were collected as well as their medical history. Patients were allocated into three groups: control, subthreshold insomnia, and insomnia. Pain intensity, climacteric symptoms and objective sleep pattern were compared between groups.

RESULTS

Postmenopausal women with insomnia had statistically significant higher pain interference in their activities (e.g. relationships with other people, enjoyment of life and sleep) than controls, and had more severe climacteric symptoms. There were no statistically significant differences in pain intensity and objective sleep pattern between groups.

CONCLUSIONS

Insomnia status affected climacteric symptoms and pain interference, but not pain intensity in postmenopausal women. Women with insomnia had higher rates of climacteric symptoms than those without insomnia or those with subthreshold insomnia. No changes in objective sleep pattern were found.

Effect of Continuous Positive Airway Pressure Treatment on Health-Related Quality of Life and Sleepiness in High Cardiovascular Risk Individuals With Sleep Apnea: Best Apnea Interventions for Research (BestAIR) Trial

Study Objectives

The long-term effect of continuous positive airway pressure (CPAP) on health-related quality of life (HRQOL) in patients with high cardiovascular disease risk and obstructive sleep apnea (OSA) without severe sleepiness is uncertain. We aimed to determine the effect of CPAP treatment on HRQOL in individuals with moderate or severe OSA and cardiovascular disease (CVD) or multiple CVD risk factors without severe sleepiness.

Methods

In this randomized, controlled, parallel group study, 169 participants were assigned to treatment with CPAP or the control group (conservative medical therapy [CMT] or CMT with sham CPAP). Analyses were based on an intention-to-treat approach. Linear mixed effect models were fitted to compare the changes in the Medical Outcomes Study Short Form-36 (SF-36) and in subjective sleepiness (Epworth Sleepiness Scale [ESS]) between groups from baseline to the average of 6- and 12-month measurements.

Results

CPAP improved several domains of HRQOL including bodily pain (treatment effect 9.7 [95% confidence interval, CI 3.9 to 15.4]; p = .001), vitality (5.7 [95% CI 1.5 to 9.9]; p = .008), general health (8.2 [95% CI 3.7 to 12.7]; p < .001), physical functioning (5.5 [95% CI 1.1 to 10.0]; p = .016), and the physical health summary score (3.3 [95% CI 1.4 to 5.3]; p = .001). CPAP also resulted in less daytime sleepiness (mean change in ESS -1.0 point [95% CI -2.0 to -0.0]; p = .040).

Conclusions

In patients with moderate-severe OSA at high risk of cardiovascular events and without severe sleepiness, CPAP improved daytime sleepiness and multiple domains of HRQOL over 6 to 12 months of follow-up, with the largest improvement observed for bodily pain.

Causal Mediation in the Development of Painful Temporomandibular Disorder

We explored causal mediation of sleep quality and perceived stress in development of painful temporomandibular disorder (TMD). Sleep quality and perceived stress were assessed at baseline and quarterly intervals thereafter in 2,737 initially TMD-free adults in the Orofacial Pain Prospective Evaluation and Risk Assessment study (OPPERA) prospective cohort study. During follow-up, incident TMD cases were classified using research diagnostic criteria. Mediation analysis was conducted using a weighted Cox proportional hazards regression model that estimated hazard ratios (HRs) and 95% confidence limits (CL) of first-onset TMD. Models determined whether: 1) poor sleep quality during follow-up mediated the effect of baseline perceived stress on first-onset TMD, and 2) perceived stress during follow-up mediated the effect of baseline poor sleep quality on first-onset TMD. In both analyses, the total effect was decomposed into natural direct and indirect effects. Poor baseline sleep quality led to heightened perceived stress that then contributed to TMD development. When the total effect of poor sleep quality (HR = 2.10, CL = 1.76, 2.50) was decomposed, 34% of its effect was mediated by perceived stress (indirect effect HR = 1.29, CL = 1.06, 1.58). The effect of perceived stress on first-onset TMD was not mediated by sleep quality. Improving sleep may avert escalation of stress, limiting effects of both factors on TMD development.

PERSPECTIVE

Causal mediation analysis highlights mechanisms by which poor sleep quality promotes development of TMD. First, poor sleep quality exerts a direct effect on pain. Second, it triggers a heightened perception of stress, which acts as an intermediate factor in the causal pathway between poor sleep quality and first-onset TMD pain.

Prospective Mediation Models of Sleep, Pain, and Daily Function in Children With Arthritis Using Ecological Momentary Assessment

OBJECTIVES

Sleep is an emerging area of concern in children with juvenile idiopathic arthritis (JIA). Research shows the presence of poor sleep quality and related adverse outcomes in pediatric pain populations, including JIA, but few studies have examined the prospective patterns of association between sleep and associated outcomes. This prospective study evaluated the direction and magnitude of associations between subjective sleep characteristics (sleep quality, difficulty initiating sleep, and sleep duration), pain intensity, and functional limitations in children with JIA. We hypothesized that pain intensity would partially mediate the relationship between sleep and functional limitations.

METHODS

Children and adolescents with JIA (n=59; age range, 8 to 18 y) recruited during clinic visits, completed smartphone-based diaries for 1 month. Subjective sleep characteristics were reported each morning; pain and functioning were assessed 3 times daily.

RESULTS

As hypothesized, the associations between sleep quality and functional limitations and between difficulty initiating sleep and functional limitations were partially mediated by pain intensity, at any given moment (z=-3.27, P=0.001, z=2.70, P<0.05). Mediation was not detected in a model testing the association between sleep duration, pain intensity, and functional limitations (z=-0.58, P=0.56).

DISCUSSION

Results suggest that sleep is integral to understanding the momentary association between pain intensity and functioning in children with JIA.

A Single Arm Pilot Trial of Brief Cognitive Behavioral Therapy for Insomnia in Adolescents with Physical and Psychiatric Comorbidities

STUDY OBJECTIVES

The majority of adolescents with chronic insomnia have physical health or psychiatric comorbidities; insomnia is also associated with greater negative daytime symptoms (e.g., depressive symptoms) and reduced overall health-related quality of life (HRQOL). However, to date, there has been limited attention to treatment of insomnia in this population. The purpose of this study was to determine the preliminary efficacy of a brief cognitive behavioral therapy for insomnia (CBT-I) intervention on sleep, psychological symptoms, and HRQOL outcomes in adolescents with insomnia and co-occurring physical or psychiatric comorbidities.

METHODS

We conducted a single arm pilot trial in which 40 youth (mean age = 14.93, standard deviation = 1.89) with insomnia and physical or psychiatric comorbidities (e.g., depression, chronic pain, anxiety, gastrointestinal problems) received CBT-I in four individual treatment sessions over 4 to 6 w. Adolescents completed 7 days of wrist actigraphy and self-report measures of insomnia, sleep quality and behaviors, psychological symptoms, and HRQOL outcomes at pretreatment, immediate posttreatment, and 3-mo follow-up.

RESULTS

CBT-I was associated with improvements in self-reported measures of sleep including insomnia symptoms, sleep quality, sleep hygiene, pre-sleep arousal, and sleep onset latency. Psychological symptoms and HRQOL also improved. Effects were generally sustained at 3-mo follow-up.

CONCLUSIONS

CBT-I may be efficacious for adolescents with co-occurring physical and mental health comorbidities; future randomized controlled trials are needed to test the effect of CBT-I on sleep, psychological symptoms, and HRQOL and to evaluate maintenance of treatment effects over longer time periods.

Chronic pain in adolescence and internalizing mental health disorders: a nationally representative study

Chronic pain in childhood and adolescence has been shown to heighten the risk for depressive and anxiety disorders in specific samples in adulthood; however, little is known about the association between a wider variety of chronic pains and internalizing mental health disorders. Using nationally representative data, the objectives of this study were to establish prevalence rates of internalizing mental health disorders (anxiety and depressive disorders) among cohorts with or without adolescent chronic pain, and to examine whether chronic pain in adolescence is associated with lifetime history of internalizing mental health disorders reported in adulthood. Data from the National Longitudinal Study of Adolescent to Adult Health (Add Health) was used (N = 14,790). Individuals who had chronic pain in adolescence subsequently reported higher rates of lifetime anxiety disorders (21.1% vs 12.4%) and depressive disorders (24.5% vs 14.1%) in adulthood as compared with individuals without a history of adolescent chronic pain. Multivariate logistic regression confirmed that chronic pain in adolescence was associated with an increased likelihood of lifetime history of anxiety disorders (odds ratio: 1.33; 95% confidence interval: 1.09-1.63, P = 0.005) and depressive disorders (odds ratio: 1.38; confidence interval: 1.16-1.64, P < 0.001) reported in adulthood. Future research is needed to examine neurobiological and psychological mechanisms underlying these comorbidities.

Sleep Fragmentation Hypersensitizes Healthy Young Women to Deep and Superficial Experimental Pain

The effect of sleep deprivation on pain sensitivity has typically been studied using total and partial sleep deprivation protocols. These protocols do not mimic the fragmented pattern of sleep disruption usually observed in individuals with clinical pain conditions. Therefore, we conducted a controlled experiment to investigate the effect of sleep fragmentation on pain perception (deep pain: forearm muscle ischemia, and superficial pain: graded pin pricks applied to the skin) in 11 healthy young women after 2 consecutive nights of sleep fragmentation, compared with a normal night of sleep. Compared with normal sleep, sleep fragmentation resulted in significantly poorer sleep quality, morning vigilance, and global mood. Pin prick threshold decreased significantly (increased sensitivity), as did habituation to ischemic muscle pain (increased sensitivity), over the course of the 2 nights of sleep fragmentation compared with the night of normal sleep. Sleep fragmentation did not increase the maximum pain intensity reported during muscle ischemia (no increase in gain), and nor did it increase the number of spontaneous pains reported by participants. Our data show that sleep fragmentation in healthy, young, pain-free women increases pain sensitivity in superficial and deep tissues, indicating a role for sleep disruption, through sleep fragmentation, in modulating pain perception.

PERSPECTIVE

Our findings that pain-free, young women develop hyperalgesia to superficial and deep muscle pain after short-term sleep disruption highlight the need for effective sleep management strategies in patients with pain. Findings also suggest the possibility that short-term sleep disruption associated with recurrent acute pain could contribute to increased risk for future chronic pain conditions.

Patient phenotyping in clinical trials of chronic pain treatments: IMMPACT recommendations

There is tremendous interpatient variability in the response to analgesic therapy (even for efficacious treatments), which can be the source of great frustration in clinical practice. This has led to calls for "precision medicine" or personalized pain therapeutics (ie, empirically based algorithms that determine the optimal treatments, or treatment combinations, for individual patients) that would presumably improve both the clinical care of patients with pain and the success rates for putative analgesic drugs in phase 2 and 3 clinical trials. However, before implementing this approach, the characteristics of individual patients or subgroups of patients that increase or decrease the response to a specific treatment need to be identified. The challenge is to identify the measurable phenotypic characteristics of patients that are most predictive of individual variation in analgesic treatment outcomes, and the measurement tools that are best suited to evaluate these characteristics. In this article, we present evidence on the most promising of these phenotypic characteristics for use in future research, including psychosocial factors, symptom characteristics, sleep patterns, responses to noxious stimulation, endogenous pain-modulatory processes, and response to pharmacologic challenge. We provide evidence-based recommendations for core phenotyping domains and recommend measures of each domain.

Longitudinal and Temporal Associations Between Daily Pain and Sleep Patterns After Major Pediatric Surgery

Approximately 20% of children develop persistent pain after major surgery. Sleep disruption has been implicated as a predictor of children's acute postsurgical pain. However, perioperative sleep patterns have not been longitudinally assessed, and the role of sleep in persistence of postsurgical pain has not been explored. We aimed to examine sleep patterns over 4 months in children having major surgery, and temporal relationships between daily sleep and pain. Sixty children age 10 to 18 (mean = 14.7) years having major surgery completed 7 days of actigraphy sleep monitoring (sleep duration, efficiency), twice daily electronic diaries (sleep quality, pain intensity, medication use), and validated questionnaires at presurgery, 2 weeks, and 4 months postsurgery. Generalized linear models, controlling for age, sex, naps, and medication, showed sleep quality (β [B] = -.88, P < .001) and efficiency (B = -1.50, P = .036) were significantly reduced at 2 weeks compared with presurgery, and returned to baseline by 4 months. Poorer night-time sleep quality was significantly associated with greater next day pain intensity (B = -.15, P = .005). Sleep duration and efficiency were not associated with subsequent pain; daytime pain was not associated with subsequent sleep. Findings suggest sleep quality may be an important target for intervention after surgery in children; research is needed to understand how other sleep parameters may relate to recovery.

PERSPECTIVE

This study assessed longitudinal sleep patterns over 4 months after major pediatric surgery using actigraphy, diaries, and validated measures. Sleep quality and efficiency were significantly reduced at 2 weeks. Poorer sleep quality was associated with greater next day pain intensity suggesting that sleep quality may be an important target for intervention.

Foot and ankle history and clinical examination: A guide to everyday practice

This review summarises the key points in taking a history and performing a comprehensive clinical examination for patients with foot and/or ankle problems. It is a useful guide for residents who are preparing for their specialty exams, as well as family doctors and any other doctor who has to deal with foot and ankle problems in adults.

Sleep problems and pain: a longitudinal cohort study in emerging adults

Sleep and pain are thought to be bidirectional related on a daily basis in adolescents with chronic pain complaints. In addition, sleep problems have been shown to predict the long-term onset of musculoskeletal pain in middle-aged adults. Yet, the long-term effects of sleep problems on pain duration and different types of pain severity in emerging adults (age: 18-25) are unknown. This study investigated the cross-sectional and longitudinal relationship between sleep problems and chronic pain, and musculoskeletal pain, headache, and abdominal pain severity in a general population of emerging adults. We studied whether these relationships were moderated by sex and whether symptoms of anxiety and depression, fatigue, or physical inactivity mediated these effects. Data of participants from the longitudinal Dutch TRacking Adolescents' Individual Lives Survey were used. Follow-up data were collected in 1753 participants who participated in the fourth (N = 1668, mean age: 19.0 years [SD = 0.6]) and/or fifth (N = 1501, mean age: 22.3 years [SD = 0.6]) assessment wave. Autoregressive cross-lagged models were used for analyses. Sleep problems were associated with chronic pain, musculoskeletal pain, headache and abdominal pain severity, and predicted chronic pain and an increase in musculoskeletal pain severity at 3 years of follow-up. This prospective effect was stronger in females than in males and was mediated by fatigue but not by symptoms of anxiety and depression or physical inactivity. Only abdominal pain had a small long-term effect on sleep problems. Our results suggest that sleep problems may be an additional target for treatment in female emerging adults with musculoskeletal pain complaints.

Measuring Treatment Outcomes in Comorbid Insomnia and Fibromyalgia: Concordance of Subjective and Objective Assessments

STUDY OBJECTIVES

In insomnia, actigraphy tends to underestimate wake time compared to diaries and PSG. When chronic pain co-occurs with insomnia, sleep may be more fragmented, including more movement and arousals. However, individuals may not be consciously aware of these arousals. We examined the baseline concordance of diaries, actigraphy, and PSG as well as the ability of each assessment method to detect changes in sleep following cognitive behavioral therapy for insomnia (CBT-I).

METHODS

Adults with insomnia and fibromyalgia (n = 113) were randomized to CBT-I, CBT for pain, or waitlist control. At baseline and posttreatment, participants completed one night of PSG and two weeks of diaries/actigraphy.

RESULTS

At baseline, objective measures estimated lower SOL, higher TST, and higher SE than diaries (ps < 0.05). Compared to PSG, actigraphic estimates were higher for SOL and lower for WASO (ps < 0.05). Repeated measures ANOVAs were conducted for the CBT-I group (n = 15), and significant method by time interactions indicated that the assessment methods differed in their sensitivity to detect treatment-related changes. PSG values did not change significantly for any sleep parameters. However, diaries showed improvements in SOL, WASO, and SE, and actigraphy also detected the WASO and SE improvements (ps < 0.05).

CONCLUSIONS

Actigraphy was generally more concordant with PSG than with diaries, which are the recommended assessment for diagnosing insomnia. However, actigraphy showed greater sensitivity to treatment-related changes than PSG; PSG failed to detect any improvements, but actigraphy demonstrated changes in WASO and SE, which were also found with diaries. In comorbid insomnia/fibromyalgia, actigraphy may therefore have utility in measuring treatment outcomes.

Correlation of Disturbed Sleep and Cancer Stress

To illuminate the course of insomnia in the presence of an acute comorbidity, we examined the association between insomnia severity and breast cancer symptom severity over time and determined if this association varies with insomnia history and presleep arousal. Twenty-nine newly diagnosed breast cancer patients, who also exhibited insomnia, completed sleep diary and cancer symptom severity questionnaires every other week (total of 28 days) over 7 weeks, as well as baseline and postobservation measures. Participants were defined as having insomnia prior to cancer (IPC) or insomnia secondary to cancer (ISC) based on precancer sleep status. Insomnia and cancer symptom severity were strongly correlated at baseline but significantly declined over the evaluation period. Among ISC individuals, there was an association between sleep severity and cancer severity at baseline but not 7 weeks later. IPC individuals showed a consistent pattern of no significant association between sleep severity and cancer symptom severity. IPC had higher levels of cognitive presleep arousal than ISC. The current study documented the evolution of the relation between insomnia and breast cancer symptom severity over time and identified factors (premorbid insomnia and presleep hyperarousal) that may influence this association.

Reciprocal Relationship Between Sleep Macrostructure and Evening and Morning Cellular Inflammation in Rheumatoid Arthritis

OBJECTIVE

This study examined the reciprocal associations between sleep macrostructure and levels of cellular inflammation in rheumatoid arthritis (RA) patients and controls.

METHODS

RA patients (n = 24) and matched controls (n = 48) underwent all-night polysomnography, along with assessment of spontaneous- and Toll-like receptor-4-stimulated monocytic production of tumor necrosis factor α (TNF) and interleukin (IL)-6 at 11:00 PM and 8:00 AM.

RESULTS

As compared with controls, RA patients showed lower levels of sleep efficiency (mean [standard deviation], 88.1 [6.1] versus 83.8 [7.0]), a higher percentage stage 3 sleep (9.3 [6.4] versus 13.1 [6.9]), and higher levels of percentage of monocytes either spontaneously expressing TNF at 11:00 PM (log transformed, 1.07 [0.28] versus 1.22 [0.17]), and higher Toll-like receptor-4-stimulated production of IL6 at 8:00 AM (log transformed, 3.45 [0.80] versus 3.83 [0.39]). Higher levels of stimulated production of TNF at 11:00 PM were associated with higher sleep efficiency (0.74). In turn, sleep efficiency had a countervailing relationship on TNF production at 8:00 AM (-0.64). Higher levels of spontaneous and stimulated production of IL6 at 11:00 PM were associated with more stage 3 (0.39), stage 4 (0.43), and slow-wave sleep (0.49), with evidence that stage 4 had a countervailing relationship on IL6 production at 8:00 AM (-0.60).

CONCLUSIONS

RA patients show evidence of sleep fragmentation, greater sleep depth, and higher levels of cellular inflammation. Sleep maintenance and sleep depth show countervailing relationships with evening and morning levels of monocytic production of TNF and IL-6, respectively, which support the hypothesis of a feedback loop between sleep maintenance, slow-wave sleep, and cellular inflammation that is cytokine specific.

The buffering role of positive affect on the association between pain intensity and pain related outcomes

Objectives

Chronic pain is a significant problem worldwide and is associated with significant elevations in negative affect, depressive symptoms, sleep problems, and physical dysfunction. Positive affect could potentially buffer the impact of pain on patient functioning. If it does, then positive affect could be directly targeted in treatment to benefit individuals with chronic pain. The purpose of this study was to test for such moderating effects.

Methods

This was a cross-sectional study, we administered measures of pain intensity, depressive symptoms, sleep problems, pain interference, and positive and negative affect to 100 individuals with chronic back or knee pain in a single face-to-face assessment session.

Results

The associations between pain intensity and negative affect, and between pain intensity and depressive symptoms were moderated by positive affect. This moderation effect was explained by the fact that participants with low positive affect evidenced strong associations between pain intensity and both depression and negative affect; participants with high positive affect, on the other hand, evidenced weak and non-significant associations between pain intensity and both depression and negative affect. Positive affect did not moderate the associations between pain intensity and either sleep problems or pain interference.

Conclusion

The findings are consistent with the possibility that positive affect may buffer the impact of pain intensity on negative affect and depressive symptoms. Longitudinal and experimental research is needed to determine the potential benefits of treatments that increase positive affect on negative affect and depressive symptoms in chronic pain populations.

Implications

The study findings suggest the possibility that “positive psychology” interventions which increase positive affect could benefit individuals with chronic pain by reducing the impact of pain on negative outcomes. Research to test this possibility is warranted.