A preliminary examination of the effects of childhood abuse and resilience on pain and physical functioning in patients with knee osteoarthritis.

OBJECTIVES: We examined associations of a self-reported history of childhood abuse with pain and physical functioning in patients with knee osteoarthritis (KOA) awaiting total knee arthroplasty (TKA). We also explored the potential moderating effects of positive childhood experiences (PCEs), an index of resilience, on these associations. METHODS: Prior to TKA, participants with KOA awaiting surgery (N = 239) completed self-report measures of adverse childhood experiences (ACEs), PCEs, pain, and physical functioning. We evaluated associations of pain and physical functioning (Brief Pain Inventory [BPI] and Western Ontario and McMaster University of Osteoarthritis Index [WOMAC]) based on the experience of ACEs (childhood abuse), with PCEs (childhood happiness and supportive parental care) as potential moderators. RESULTS: Greater exposure to childhood abuse was positively correlated with BPI pain interference as well as WOMAC pain and functioning scores. Additionally, childhood happiness and supportive parental care moderated the positive associations of childhood abuse with pain and physical functioning; though, surprisingly, the adverse effects of childhood abuse on these outcomes were more pronounced among participants with high levels of childhood happiness and supportive parental care. CONCLUSION: Overall, results show an association between a self-reported history of childhood abuse and pain and functioning in patients with KOA awaiting TKA. However, PCEs did not protect against the negative consequences of childhood abuse in our cohort. Further research is needed to validate these associations and gain a more comprehensive understanding of the complex interplay between childhood abuse and PCEs and their potential influences on pain experiences in adults with chronic pain conditions, including KOA.

The association between changes in clinical pain severity and IL-6 reactivity among patients undergoing total knee Arthroplasty: The moderating role of change in insomnia.

Knee osteoarthritis (KOA) is linked to an enhanced release of interleukin-6 (IL-6). Increased levels of IL-6 are associated with greater pain and insomnia. While total knee arthroplasty (TKA) typically results in the reduction of pain, for a subgroup of patients, pain does not improve. Understanding patients' propensity to upregulate IL-6 may provide insight into variation in the clinical success of TKA for improving pain, and insomnia may play an important modulatory role. We investigated the association between pre- and post-surgical changes in clinical pain and IL-6 reactivity, and whether change in insomnia moderated this association. Patients (n = 39) with KOA came in-person before and 3-months after TKA. At both visits, patients completed validated measures of clinical pain and insomnia, as well as underwent quantitative sensory testing (QST). Blood samples were collected to analyze IL-expression both before and after QST procedures to assess changes in IL-6 in response to QST (IL-6 reactivity). Patients were categorized into two groups based on change in clinical pain from pre- to post-surgery: 1) pain decreased > 2 points (pain improved) and 2) pain did not decrease > 2 points (pain did not improve). Based on this definition, 49 % of patients had improved pain at 3-months. Among patients with improved pain, IL-6 reactivity significantly decreased from pre- to post-surgery, whereas there was no significant change in IL-6 reactivity among those whose pain did not improve. There was also a significant interaction between pain status and change in insomnia, such that among patients whose insomnia decreased over time, improved pain was significantly associated with a reduction in IL-6 reactivity. However, among patients whose insomnia increased over time, pain status and change in IL-6 reactivity were not significantly associated. Our findings suggest that the resolution of clinical pain after TKA may be associated with discernible alterations in pro-inflammatory responses that can be measured under controlled laboratory conditions, and this association may be moderated by perioperative changes in insomnia. Randomized controlled trials which carefully characterize the phenotypic features of patients are needed to understand how and for whom behavioral interventions may be beneficial in modulating inflammation, pain, and insomnia.

Adverse Childhood Experiences and Chronic Low Back Pain In Adulthood: The Role of Emotion Regulation.

Chronic low back pain (cLBP) is characterized by biopsychosocial determinants that collectively result in substantial burden at the individual, community, and healthcare system levels. A growing body of literature suggests that childhood adversity is longitudinally associated with the development and maintenance of various chronic pain conditions in adulthood. Little research has investigated the psychological processes that might underlie the association between adverse childhood experiences (ACEs) and cLBP. Emotion regulation comprises a substantive part of the subjective experience of pain and may be a potential mechanism through which ACEs contribute to cLBP etiology and maintenance. Thus, the current study examined the extent to which emotion dysregulation mediated the relationship between ACEs and pain severity (pain at rest and movement-evoked pain) in adults with cLBP. Participants included 183 adults (53.0% female, 62.5% non-Hispanic Black) between the ages of 18 and 85 with cLBP. Participants self-reported on ACEs, pain, difficulties in emotion regulation, depression, and completed brief physical function tasks. In data analytic models, sociodemographic variables were included as covariates. Mediation analyses revealed that emotion regulation mediated the relationship between ACEs and cLBP severity at rest (indirect effect = 0.15 (95% CI [0.06 to 0.25]) and with movement (indirect effect = 1.50 (95% CI [0.69 to 2.57]). Findings suggest ACEs are linked to cLBP severity in adulthood though difficulties in emotion regulation. This aligns with research demonstrating that childhood maltreatment can lead to difficulties in emotion regulation which perpetuate over the lifespan to impact adult health outcomes. TRIAL REGISTRATION: This study utilized baseline data collected as part of a parent trial titled "Examining Racial and SocioEconomic Disparities in Chronic Low Back Pain" (ERASED - ClinicalTrials.gov ID: NCT03338192). PERSPECTIVE: This study presents emotion dysregulation as a psychological pathway through which childhood adversity may contribute to chronic low back pain in adulthood. This work may bolster our understanding of social experiences as risk factors for chronic pain, while identifying targets for clinical intervention.

Age, Race, Ethnicity, and Sex of Participants in Clinical Trials Focused on Chronic Pain.

There is limited data on equitable inclusion in chronic pain trials. We aimed to 1) identify the frequency of reporting age, race, ethnicity, and sex in clinical trials targeting chronic pain, and 2) compare sociodemographic representation to the United States (US) population. We examined US-based intervention trials for chronic pain initiated between 2007 and 2021 and registered on ClinicalTrials.gov. We 1) assessed the frequency of reporting each demographic variable, 2) compared representation with US population estimates, and 3) explored change in reporting over time. Of 501 clinical trials, the frequency of reporting was as follows: 36.9% reported older adults, 54.3% reported race, 37.4% reported ethnicity, and 100% reported sex. Rates of race and ethnicity reporting increased, but older adult age reporting decreased over time (ps < .00001). Compared to 2020 US population estimates, there was an equitable representation of older adults, under-representation of individuals identifying as American Indian or Alaska Native (.8% vs .6%), Asian (5.6% vs 2.9%), Black or African American (12.6% vs 12.2%), with more than one race (2.9% vs 1.2%), and Hispanic/Latino (16.9% vs 14.1%). There was an over-representation of individuals identifying as Native Hawaiian or Pacific Islander (.2% vs .5%) or White (70.4% vs 72.9%), and of females (50.8% vs 68.4%). Some representation rates varied by chronic pain condition. Reporting of older adult age, race, and ethnicity was low in chronic pain trials in ClinicalTrials.gov, reinforcing the need for adhering to reporting guidelines. Representation varied across trials compared with US population data, particularly among those identifying as Hispanic/Latino and certain minority racial groups. PERSPECTIVE: Despite initiatives to increase the reporting of demographic information, doing so in clinical pain trials is far from ubiquitous. Moreover, efforts to improve diversity in these trials continue to be insufficient. Indeed, Black, Indigenous, and People of Color (BIPOC) remain under-represented in clinical pain trials.

Race-specific associations: inflammatory mediators and chronic low back pain.

ABSTRACT: Chronic low back pain (cLBP) is a global health crisis that disproportionately burdens non-Hispanic Black (NHB) individuals, compared with those who identify as non-Hispanic White (NHW). Despite the growing personal and societal impact of cLBP, its biological underpinnings remain poorly understood. To elucidate the biological factors that underlie the racial disparities in cLBP, this study sought to determine whether inflammatory mediators associated with pain interference (PI), pain at rest (PAR), and movement-evoked pain (MEP) differ as a function of racial identity. Blood samples were collected from 156 individuals with cLBP (n = 98 NHB participants, n = 58 NHW participants). Enzyme-linked immunosorbent assay and multiplex assays were used to quantify concentrations of proinflammatory (fibrinogen, C-reactive protein [CRP], serum amyloid A, tumor necrosis factor α [TNF-α], and interleukin [IL]-1α, IL-1ß, and IL-6) and anti-inflammatory markers (IL-4 and IL-13). Spearman rho correlations were used to assess associations among markers of inflammation and PI, PAR, and MEP using the Brief Pain Inventory-Short Form. Analyses revealed that for NHW patients, CRP, serum amyloid A, and IL-6 were positively associated with cLBP outcomes and IL-4 was inversely associated with PAR and MEP. However, for NHB patients, only IL-1α was positively associated with PAR. Our findings suggest that, while there are associations between inflammation and cLBP outcomes, the biomarkers that underlie the inflammation could very well differ as a function of racialized minority group. However, more research with racially inclusive samples is needed to elucidate the mechanisms that may contribute to racial disparities in cLBP.

The role of sleep disturbance in reduced accuracy on a divided attention task among patients with fibromyalgia.

Introduction: Patients with fibromyalgia show impaired cognitive performance compared with healthy, pain-free controls. Sleep disturbance, anxiety, and depression are highly prevalent among patients with fibromyalgia, and each is associated with impaired cognitive performance. Yet, limited work has explored whether psychosocial factors contribute to group differences in cognitive performance. Objectives: This secondary data analysis investigated differences in cognitive performance between patients with fibromyalgia and healthy controls, and whether psychosocial factors accounted for these differences. Methods: Adults with fibromyalgia (N = 24) and healthy, pain-free controls (N = 26) completed 2 cognitive tasks and the Patient-Reported Outcomes Measurement Information System sleep disturbance, anxiety, and depression short forms. Independent samples t tests were used to test for differences in cognitive performance between patients with fibromyalgia and healthy controls. Pearson correlations were conducted to examine associations between psychosocial factors and cognitive performance. Psychosocial factors significantly related to cognitive performance were explored as potential mediators of group differences in cognitive performance. Results: Patients with fibromyalgia demonstrated poorer accuracy for divided attention compared with healthy controls, and sleep disturbance mediated this group difference. On the attentional switching task, healthy controls showed a greater switch-cost for accuracy compared with patients with fibromyalgia, but there was no group difference in reaction time. Anxiety and depression were not related to cognitive performance. Conclusion: We found that patients with fibromyalgia reported greater sleep disturbance and, in turn, had poorer accuracy on the divided attention task. Sleep disturbance is modifiable with behavioral interventions, such as cognitive behavioral therapy, and may be a target for improving sleep quality and cognitive performance among patients with fibromyalgia.

Quantitative somatosensory testing of the abdomen: establishing initial reference values across developmental age and biological sex.

ABSTRACT: Abdominal pain is a common symptom of several debilitating conditions (eg, inflammatory bowel disease, irritable bowel syndrome, and endometriosis) and affects individuals throughout their lifespan. Quantitative sensory testing (QST) reference values exist for many body sites but not the abdomen. Using a QST battery adapted from the German Research Network on Neuropathic Pain, we collected QST data on the upper and lower abdomen in 181 pain-free participants, ages 12 to 50 years, to establish reference values by age and biological sex. The normative values are presented as medians for each QST measure by sex (male, n = 63; female, n = 118) and across 3 age categories (adolescents: 12-19 years, n = 48; young adults: 20-30 years, n = 87; and adults: 31-50 years, n = 46). Evaluating the sensory functioning of the abdomen and characterizing ranges of QST measures is an essential first step in understanding and monitoring the clinical course of sensory abnormalities in patients with underlying diseases affecting the abdomen and pelvis. The impact of age and development on sensory functioning is necessary, given age-related changes in pain perception and modulation.

Change in Pain During Physical Activity Following Total Knee Arthroplasty: Associations With Improved Physical Function and Decreased Situational Pain Catastrophizing.

Background and Objectives: Knee osteoarthritis is one of the primary causes of chronic pain among older adults and because of the aging population, the number of total knee arthroplasties (TKAs) performed is exponentially increasing. While pain reduction is a goal of TKA, movement-evoked pain is rarely assessed pre- and post-TKA. We characterized the distributions of change in pain, function, and situational catastrophizing in patients from presurgery to 3 months postsurgery and explored associations among these pre-post changes. Research Design and Methods: This prospective study longitudinally assessed movement-evoked pain, function, and situational catastrophizing in patients with knee osteoarthritis (N = 92) using in-person performance-based tests (6-min walk test [6MWT], stair-climb test [SCT]) prior to and 3 months after TKA. Patients also completed the Western Ontario McMaster Universities Scales (WOMAC) pain and function subscales, and Pain Catastrophizing Scale, presurgery and 3- and 6-months postsurgery. Results: Movement-evoked pain and function on performance tests significantly improved from pre- to post-TKA. Improved SCT function was associated with reduced SCT pain and catastrophizing. Similarly, reduced pain during the SCT was associated with reduced catastrophizing during the SCT. However, 6MWT function was not associated with 6MWT pain or catastrophizing; yet reduced pain during the 6MWT was associated with reduced catastrophizing during the 6MWT. Reduced movement-evoked pain during both performance tests was consistently associated with improved WOMAC function and pain, whereas improved function on performance tests was inconsistently associated with WOMAC function and pain. Notably, greater movement-evoked pain on both performance tests at 3-month post-TKA was associated with worse WOMAC function and pain at 6 months, whereas better function on performance tests at 3 months was associated with better WOMAC function, but not related to WOMAC pain at 6 months. Discussion and Implications: Findings highlight the importance of situation-specific and in vivo assessments of pain and catastrophizing during physical activity.

The mediating effect of social functioning on the relationship between catastrophizing and pain among patients with chronic low back pain.

OBJECTIVE: Pain catastrophizing can be characterized as an interpersonal form of coping used to elicit support or empathy from others. Despite intentions of increasing support, catastrophizing can impair social functioning. While considerable work has addressed the relationship between catastrophizing and pain, limited empirical work has examined this relationship within a social context. First, we examined the role of catastrophizing as a potential contributor to group differences (chronic low back pain [cLBP] vs pain-free controls) in social functioning. Then we conducted a follow-up, exploratory analysis to examine the relationships between catastrophizing, social functioning, and pain within the subgroup of participants with cLBP. METHODS: In this observational study, participants with cLBP (N = 62) and pain-free controls (N = 79) completed validated measures of pain, social functioning, and pain catastrophizing. A mediation analysis was conducted to examine whether catastrophizing mediated group differences (cLBP vs controls) in social functioning. A follow-up, exploratory mediation analysis then tested whether social functioning mediated the association between catastrophizing and pain within the subgroup of cLBP participants. RESULTS: Participants with cLBP reported higher levels of pain, impaired social functioning, and higher catastrophizing compared to pain-free controls. Catastrophizing partially mediated the group difference in impaired social functioning. Additionally, social functioning mediated the association between higher catastrophizing and greater pain within the subgroup of cLBP participants. CONCLUSIONS: We showed that impaired social functioning was driving the relationship between higher pain catastrophizing and worse pain among participants with cLBP. Interventions, such as cognitive behavioral therapy, should address catastrophizing in individuals with cLBP, while simultaneously improving social functioning.

Perioperative insomnia trajectories and functional outcomes after total knee arthroplasty.

ABSTRACT: Longitudinal total knee arthroplasty (TKA) studies indicate that a substantial percentage of patients continue to experience clinically significant pain and functional impairment after surgery. Insomnia has been associated with poorer surgical outcomes; however, previous work has largely focused on long-term postsurgical insomnia. This study builds on previous work by examining sleep and pain outcomes about perioperative insomnia trajectories. Insomnia symptoms (using the Insomnia Severity Index) during the acute perioperative period (2 weeks pre-TKA to 6 weeks post-TKA) were used to classify participants into perioperative insomnia trajectories: (1) No Insomnia (ISI < 8), (2) New Insomnia (baseline < 8; postoperative ≥ 8 or ≥6-point increase), (3) Improved Insomnia (baseline ≥ 8, postoperative < 8 or ≥6-point decrease), and (4) Persistent Insomnia (ISI ≥ 8). Insomnia, pain, and physical functioning were assessed in participants with knee osteoarthritis (n = 173; M age = 65 ± 8.3, 57.8% female) at 5 time points: 2 weeks pre-TKA, post-TKA: 6 weeks, 3 months, 6 months, and 12 months. Significant main effects were seen for insomnia trajectory and time, and trajectory-by-time interactions for postoperative insomnia, pain severity, and physical functioning ( P' s < 0.05). The Persistent Insomnia trajectory had the worst postoperative pain at all follow-ups and marked insomnia and physical functioning impairment post-TKA ( P' s < 0.05). The New Insomnia trajectory had notable long-term insomnia (6 weeks to 6 months) and acute (6 weeks) postoperative pain and physical functioning ( P' s < 0.05). Findings indicated a significant relationship between perioperative insomnia trajectory and postoperative outcomes. Results of this study suggest that targeting presurgical insomnia and preventing the development of acute postoperative insomnia may improve long-term postoperative outcomes, with an emphasis on persistent perioperative insomnia due to poorer associated outcomes.

Let's Get Physical! A Comprehensive Review of Pre- and Post-Surgical Interventions Targeting Physical Activity to Improve Pain and Functional Outcomes in Spine Surgery Patients.

The goal of this comprehensive review was to synthesize the recent literature on the efficacy of perioperative interventions targeting physical activity to improve pain and functional outcomes in spine surgery patients. Overall, research in this area does not yet permit definitive conclusions. Some evidence suggests that post-surgical interventions may yield more robust long-term outcomes than preoperative interventions, including large effect sizes for disability reduction, although there are no studies directly comparing these surgical approaches. Integrated treatment approaches that include psychosocial intervention components may supplement exercise programs by addressing fear avoidance behaviors that interfere with engagement in activity, thereby maximizing the short- and long-term benefits of exercise. Efforts should be made to test brief, efficient programs that maximize accessibility for surgical patients. Future work in this area should include both subjective and objective indices of physical activity as well as investigating both acute postoperative outcomes and long-term outcomes.

A Brief Overview: Sex Differences in Prevalent Chronic Musculoskeletal Conditions.

Musculoskeletal (MSK) pain disorders are some of the most prevalent and disabling chronic pain conditions worldwide. These chronic conditions have a considerable impact on the quality of life of individuals, families, communities, and healthcare systems. Unfortunately, the burden of MSK pain disorders does not fall equally across the sexes. Females consistently demonstrate more prevalent and severe clinical presentations of MSK disorders, and this disparity increases in magnitude with age. The aim of the present article is to review recent studies that have examined sex differences between males and females in four of the most common MSK pain disorders: neck pain, low back pain, osteoarthritis, and rheumatoid arthritis.

The Relationship of Postoperative Pain and Opioid Consumption to Postoperative Delirium After Spine Surgery.

Purpose: To examine the relationship between postoperative pain and opioid use and the development of postoperative delirium (POD), with attention to the preoperative opioid use status of patients. Methods: This was a secondary analysis of data from a prospective observational study of patients (N = 219; ≥70 years old) scheduled to undergo elective spine surgery. Maximal daily pain scores (0-10) and postoperative morphine milligram equivalents per hour (MME/hr) were determined for postoperative days 1-3 (D1-3). POD was assessed by daily in-person interviews using the Confusion Assessment Method and chart review. Results: Patients who reported regular preoperative opioid use (n = 58, 27%) reported significantly greater maximal daily pain scores, despite also requiring greater daily opioids (MME/hr) in the first 3 days after surgery. These patients were also more likely to develop POD. Interestingly, while postoperative pain scores were significantly higher in patients who developed POD, postoperative opioid consumption was not significantly higher in this group. Conclusion: POD was associated with greater postoperative pain, but not with postoperative opioid consumption. While postoperative opioid consumption is often blamed for delirium, these findings suggest that uncontrolled pain may actually be a more important factor, particularly among patients who are opioid tolerant. These findings underscore the importance of employing multimodal perioperative analgesic management, especially among older patients who have a predilection to developing POD and baseline tolerance to opioids.

The Pain and PRAYER Scale (PPRAYERS): development and validation of a scale to measure pain-related prayer.

OBJECTIVES: Prayer is a devotional practice used across religious traditions to commune with the sacred and has been used as a coping strategy for pain. Previous research on prayer as a pain coping strategy has had mixed results, with prayer associated with both greater and lesser pain depending on prayer type. To date, there has been only 1 measure of pain-related prayer, the prayer subscale of the Coping Strategies Questionnaire-Revised, which measures solely passive prayer, neglecting other types of prayer (eg, active and neutral). To better understand the relationship between pain and prayer, a comprehensive measure of prayer for pain is needed. The aim of this study was to develop and validate the Pain-related PRAYER Scale (PPRAYERS), a questionnaire exploring active, passive, and neutral petitionary prayers to God or a higher power in response to pain. METHODS: Adults with chronic pain (n = 411) completed demographic, health, and pain-related questionnaires, including PPRAYERS. RESULTS: Results of an exploratory factor analysis yielded a 3-factor structure consistent with active, passive, and neutral subscales. A confirmatory factor analysis resulted in adequate fit after the removal of 5 items. PPRAYERS showed good internal consistency and convergent and discriminant validity. DISCUSSION: These results provide preliminary validation for PPRAYERS, a novel measure for pain-related prayer.

The Experience of BIPOC Living with Chronic Pain in the USA: Biopsychosocial Factors that Underlie Racial Disparities in Pain Outcomes, Comorbidities, Inequities, and Barriers to Treatment.

PURPOSE OF REVIEW: This review synthesizes recent findings related to the biopsychosocial processes that underlie racial disparities in chronic pain, while highlighting opportunities for interventions to reduce disparities in pain treatment among BIPOC. RECENT FINDINGS: Chronic pain is a prevalent and costly public health concern that disproportionately burdens Black, Indigenous, and people of color (BIPOC). This unequal burden arises from an interplay among biological, psychological, and social factors. Social determinants of health (e.g., income, education level, and lack of access or inability to utilize healthcare services) are known to affect overall health, including chronic pain, and disproportionately affect BIPOC communities. This burden is exacerbated by exposure to psychosocial stressors (i.e., perceived injustice, discrimination, and race-based traumatic stress) and can affect biological systems that modulate pain (i.e., inflammation and pain epigenetics). Further, there are racial/ethnic disparities in pain treatment, perpetuating the cycle of undermanaged chronic pain among BIPOC.

Brief Mindfulness-Based Cognitive Behavioral Therapy is Associated with Faster Recovery in Patients Undergoing Total Knee Arthroplasty: A Pilot Clinical Trial.

OBJECTIVE: To assess whether brief mindfulness-based cognitive behavioral therapy (MBCBT) could enhance the benefits of total knee arthroplasty (TKA) in improving pain and pain-related disability. Specifically, to determine 1) whether patients who received MBCBT differed from matched controls who received treatment-as-usual with regard to postsurgical pain outcomes and 2) whether changes in pain catastrophizing, depression, or anxiety explained the potential effects of MBCBT on pain outcomes. DESIGN: Pilot clinical trial. SETTING: An academic teaching hospital serving a large urban and suburban catchment area surrounding the Boston, Massachusetts metropolitan region. SUBJECTS: Sample of 44 patients undergoing TKA. Patients who completed a brief MBCBT intervention (n = 22) were compared with age-, race-, and sex-matched controls who received treatment-as-usual (n = 22). METHODS: The MBCBT intervention included four 60-minute sessions delivered by a pain psychologist in person and via telephone during the perioperative period. Participants were assessed at baseline and at 6 weeks, 3 months, and 6 months after surgery. RESULTS: Compared with matched controls, patients who received MBCBT had lower pain severity and pain interference at 6 weeks after surgery. Group differences in outcomes were mediated by changes in pain catastrophizing but not by changes in depression or anxiety. The MBCBT group had similar reductions in pain severity and interference as the control group did at 3 and 6 months after surgery. CONCLUSIONS: This work offers evidence for a safe and flexibly delivered nonpharmacological treatment (MBCBT) to promote faster recovery from TKA and identifies change in pain catastrophizing as a mechanism by which this intervention could lead to enhanced pain-related outcomes.

Introversion, Extraversion, and Worsening of Chronic Pain Impact during Social Isolation: A Mediation Analysis.

COVID-19 social distancing mandates increased social isolation, resulting in changes in pain severity and interference among individuals with chronic pain. Differences in personality (e.g., introversion/extraversion) may modulate responses to social isolation. We examined the influence of introversion on reported social distancing-related increases in pain interference and assessed for mediators of this relationship. Individuals with chronic pain (n = 150) completed validated questionnaires 4-8 weeks after implementation of social distancing mandates. Introversion/extraversion was measured using a subscale of the Myers-Briggs Type Indicator and changes in pain and psychosocial variables were calculated by comparing participants' recalled and current scores. Association between introversion/extraversion and other variables were assessed using linear regression. A parallel mediation was used to examine mediators of the association between introversion and change in pain interference. Higher introversion was associated with a decrease in pain interference after social distancing (Rho = - .194, p = .017). Parallel mediation analysis revealed that the relationship between introversion/extraversion and change in pain interference was mediated by changes in sleep disturbance and depression, such that higher introversion was associated with less isolation-induced sleep disruption and depression, and thereby less worsening of pain interference. These findings suggest that personality factors such as introversion/extraversion should be considered when personalizing treatment of chronic pain.

Loneliness and Pain Catastrophizing Among Individuals with Chronic Pain: The Mediating Role of Depression.

Purpose: Loneliness increased during the COVID-19 pandemic and social distancing guidelines, potentially exacerbating negative cognitions about pain. The present study investigated the longitudinal relationship between loneliness, assessed during the early weeks of the pandemic, and pain catastrophizing, assessed after living in the pandemic for approximately 1 year, among chronic pain patients. We also examined whether severity of depressive symptoms mediated this association. Methods: This prospective longitudinal study recruited individuals with chronic pain (N=93) from Massachusetts using an online convenience sampling method via the platform Rally. Participants completed an initial survey early after the onset of social distancing (4/28/20-6/17/20; Time 1) and a follow-up survey 1 year later (5/21/21-6/7/21; Time 2). Participants completed validated assessments of loneliness (T1), pain catastrophizing (T2), and depression (T2). Spearman correlations and Mann-Whitney U-tests were used to explore associations among psychosocial, pain, and participant characteristics. A mediation analysis was conducted to test whether the association between loneliness and pain catastrophizing was mediated by depression. Results: Participants had a mean age of 40.6 years and were majority female (80%) and White (82%). Greater loneliness was associated with subsequent higher pain catastrophizing (b=1.23, 95% CI [0.03, 2.44]). Mediation analysis showed a significant indirect effect (b=0.57, 95% CI [0.10, 1.18) of loneliness (T1) on catastrophizing (T2) through depression (T2) while accounting for several important covariates. The direct effect of loneliness on catastrophizing was no longer significant when depression was included in the model (b=0.66, 95% CI [-0.54, 1.87]). Conclusion: Findings suggest that greater loneliness during the pandemic was associated with higher pain catastrophizing 1 year later, and severity of depression after living in the pandemic mediated this association. As loneliness, depression, and catastrophizing can all be modified with behavioral interventions, understanding the temporal associations among these variables is important for the employment of future empirically supported treatments.