Investigating mortality salience as a potential causal influence and moderator of responses to laboratory pain.

Background: Because pain can have profound ramifications for quality of life and daily functioning, understanding nuances in the interplay of psychosocial experiences with pain perception is vital for effective pain management. In separate lines of research, pain resilience and mortality salience have emerged as potentially important psychological correlates of reduced pain severity and increased tolerance of pain. However, to date, there has been a paucity of research examining potentially interactive effects of these factors on pain perception. To address this gap, the present experiment investigated mortality salience as a causal influence on tolerance of laboratory pain and a moderator of associations between pain resilience and pain tolerance within a Chinese sample. Methods: Participants were healthy young Chinese adults (86 women, 84 men) who first completed a brief initial cold pressor test (CPT) followed by measures of demographics and pain resilience. Subsequently, participants randomly assigned to a mortality salience (MS) condition completed two open-ended essay questions in which they wrote about their death as well as a death anxiety scale while those randomly assigned to a control condition completed analogous tasks about watching television. Finally, all participants engaged in a delay task and a second CPT designed to measure post-manipulation pain tolerance and subjective pain intensity levels. Results: MS condition cohorts showed greater pain tolerance than controls on the post-manipulation CPT, though pain intensity levels did not differ between groups. Moderator analyses indicated that the relationship between the behavior perseverance facet of pain resilience and pain tolerance was significantly stronger among MS condition participants than controls. Conclusions: This experiment is the first to document potential causal effects of MS on pain tolerance and Ms as a moderator of the association between self-reported behavior perseverance and behavioral pain tolerance. Findings provide foundations for extensions within clinical pain samples.

Pain Catastrophizing Dimensions Mediate the Relationship between Chronic Pain Severity and Depression.

BACKGROUND: Although past studies have found significant positive correlations of both pain severity and overall pain catastrophizing (PC) levels with depression in chronic pain samples, less is known about the extent to which specific PC dimensions (i.e., helplessness, magnification, rumination) explain links between pain severity and depression. AIM: This study assessed the relative importance of PC dimensions as mediators of relations between chronic pain severity and depression. DESIGN: A cross sectional study design was employed. METHOD: Mainland Chinese adults with chronic pain (n = 983) completed validated questionnaire measures of PC, depression, and chronic pain severity within a cross-sectional research design. RESULTS: Analyses indicated helplessness mediated the association between pain severity and depression while magnification partially mediated the association of helplessness with depression. Conversely, rumination did not make a significant contribution in the mediation model. CONCLUSIONS: The helplessness dimension of PC, in particular, may help to explain why people with more severe chronic pain are prone to co-occurring depression.

Promising Subjective and Objective Benefits of Modified Mindfulness-Based Stress Reduction Training for Chinese Adults with Chronic Pain: A Pilot Randomized Control Study.

INTRODUCTION: Mindfulness-based stress reduction (MBSR) has demonstrated its effectiveness in reducing pain-related stress in adults with chronic pain. However, the implementation of MBSR needs modifications across cultures. This pilot study reports the findings of a randomized controlled trial that investigated the effects of a culturally adaptive MBSR program on self-report and neuroimaging outcomes for chronic pain adults in China. METHODS: Sixty-seven participants were randomly assigned to the treatment group (n = 40) or the treatment-as-usual group (n = 27) group at a ratio of 1.5:1. Participants completed self-report measures of pain severity, pain interference, depression, perceived stress, pain catastrophizing, mindfulness, and resilience at baseline assessment (T1), post-treatment (T2), and 3-month follow-up (T3) assessments. Functional magnetic resonance imaging (fMRI) scanning was also performed at T1 and T3 assessments. RESULTS: For the intention-to-treat sample, the results of the mixed-effect model indicated that Group × Time interaction was significant for pain catastrophizing only (F (2, 130) = 3.51, p = 0.033). Compared with the control group, those in the MBSR group reported greater reductions in pain catastrophizing at T2 (d = - 0.60), though this effect was not maintained at T3 (d = - 0.05). Additionally, the results of completer analyses found significant Group × Time interactions for pain interference (F (2, 88) = 4.40, p = 0.015) and perceived stress (F (2, 88) = 3.13, p = 0.048), but not for other measures. Finally, both groups exhibited decreased regional homogeneity (ReHo) in the frontal lobe, while increased ReHo in the cerebellum anterior lobe was unique to the MBSR group. CONCLUSIONS: The present findings suggest that the minor modified MBSR program improves certain pain-related outcomes for Chinese adults with chronic pain. Future studies with larger samples of Chinese chronic pain patients are needed to detect the small-to-moderate benefit of MBSR on fMRI and/or other objective methods.

Individual Differences in Pain Catastrophizing and Regional Gray Matter Volume Among Community-dwelling Adults With Chronic Pain: A Voxel-based Morphology Study.

OBJECTIVES: Elevations in pain catastrophizing (PC) are associated with more severe pain, emotional distress, and impairment within samples with chronic pain. However, brain structure correlates underlying individual differences in PC are not well understood and predict more severe pain and impairment within samples with chronic pain. This study assessed links between regional gray matter volume (GMV) and individual differences in PC within a large mixed chronic pain sample. MATERIALS AND METHODS: Chinese adult community dwellers with chronic pain of at least 3 months duration (101 women and 59 men) completed self-report measures of background characteristics, pain severity, depression, and a widely validated PC questionnaire as well as a structural magnetic resonance imagining scan featuring voxel-based morphology to assess regional GMV correlates of PC. RESULTS: After controlling for demographic correlates of PC, pain severity, and depression, higher PC scores had a significant, unique association with lower GMV levels in the inferior temporal area of the right fusiform gyrus, a region previously implicated in emotion regulation. DISCUSSION: GMV deficits, particularly in right temporal-occipital emotion regulation regions, correspond to high levels of PC among individuals with chronic pain.

Nonlinear relationship between early postnatal weight gain velocity and neurodevelopmental outcomes in very-low birth weight preterm infants: A secondary analysis based on a published prospective cohort study.

Background: Extrauterine growth restriction among the very-low birth weight preterm infants (VLBWPIs) is associated with poorer cognitive development outcome, while the rapid weight gain in infancy increases the long-term risk of obesity and noncommunicable disease among VLBWPIs. However, the results of research on the association between early postnatal growth velocity and neurodevelopmental outcomes in VLBWPIs are still limited and controversial. Objective: We aimed to explore the association between the growth velocity in early postnatal and neurodevelopmental impairment (NDI) among VLBWPIs. Methods: This study was a secondary analysis of a previously published prospective cohort. It was based on data on 1,791 premature infants with a birth weight of less than 1500 g, registered in the database of the Premature Baby Foundation of Taiwan between 2007 and 2011. A binary logistic regression model was used to evaluate the association between the weight gain velocity in different periods [from birth to 6 months corrected age (CA), 6 to 12 months CA, and 12 to 24 months CA] and NDI, respectively. The generalized additive model and the smooth curve fitting (penalized spline method) were used to address nonlinearity, and a two-piece-wise binary logistic regression model was added to explain the nonlinearity further. Results: Nonlinearities were observed between NDI and the weight gain velocity from birth to 6 months CA [inflection point 20.36, inflection point: OR = 1.01, 95% CI 0.97-1.05], 6-12 months CA [inflection point 9.44, inflection point: OR = 1.05, 95% CI 1.05-(1.00, 1.11)], and 12-24 months CA [inflection point 16.00, inflection point: OR = 1.75, 95% CI 1.05-(0.96, 3.08)]. Conclusion: The neurodevelopmental benefits from a rapid weight gain velocity from birth to 24 months CA might be limited once the growth pace reaches an optimum level. It would help find a pattern of growth that facilitates optimal neurodevelopment, yet minimizes negative health consequences associated with overnutrition further.

Identifying resting state differences salient for resilience to chronic pain based on machine learning multivariate pattern analysis.

Studies have documented behavior differences between more versus less resilient adults with chronic pain (CP), but the presence and nature of underlying neurophysiological differences have received scant attention. In this study, we attempted to identify regions of interest (ROIs) in which resting state (Rs) brain activity discriminated more from less resilient CP subgroups based on multiple kernel learning (MKL). More and less resilient community-dwellers with chronic musculoskeletal pain (70 women, 39 men) engaged in structural and functional magnetic resonance imaging (MRI) scans, wherein MKL assessed Rs activity based on amplitude of low frequency fluctuations (ALFF), fractional amplitudes of low frequency fluctuations (fALFF), and regional homogeneity (ReHo) modalities to identify ROIs most salient for discriminating more versus less resilient subgroups. Compared to classification based on single modalities, multi-modal classification based on combined fALFF and ReHo features achieved a substantially higher classification accuracy rate (79%). Brain regions with the best discriminative power included those implicated in pain processing, reward, executive function, goal-directed action, emotion regulation and resilience to mood disorders though variation trends were not consistent between more and less resilient subgroups. Results revealed patterns of Rs activity that serve as possible biomarkers for resilience to chronic musculoskeletal pain.

Gray Matter Volume Differences Between More Versus Less Resilient Adults with Chronic Musculoskeletal Pain: A Voxel-based Morphology Study.

Resilience, a personality construct that reflects capacities to persevere, maintain a positive outlook and/or thrive despite ongoing stressors, has emerged as an important focus of research on chronic pain (CP). Although behavior studies have found more resilient persons with CP experience less pain-related dysfunction than less resilient cohorts do, the presence and nature of associated brain structure differences has received scant attention. To address this gap, we examined gray matter volume (GMV) differences between more versus less resilient adults with chronic musculoskeletal pain. Participants (75 women, 43 men) were community-dwellers who reported ongoing musculoskeletal pain for at least three months. More (n = 57) and less (n = 61) resilient subgroups, respectively, were identified on the basis of scoring above and below median scores on two validated resilience questionnaires. Voxel-based morphology (VBM) undertaken to examine resilience subgroup differences in GMV indicated more resilient participants displayed significantly larger GMV in the (1) bilateral precuneus, (2) left superior and inferior parietal lobules, (3) orbital right middle frontal gyrus and medial right superior frontal gyrus, and (4) bilateral median cingulate and paracingulate gyri, even after controlling for subgroup differences on demographics and measures of pain-related distress. Together, results underscored the presence and nature of specific GMV differences underlying subjective reports of more versus less resilient responses to ongoing musculoskeletal pain.

Factor Structure and Construct Validity of the Pain Resilience Scale Within Chinese Adult Chronic Musculoskeletal Pain Samples.

Recent U.S. studies of musculoskeletal pain have supported the structure and construct validity of the Pain Resilience Scale (PRS) as a pain-specific measure tapping capacities to regulate cognitions and emotions as well as behavioral perseverance despite ongoing pain. However, it is not clear whether psychometric support for the PRS extends to chronic musculoskeletal pain samples in other countries or whether PRS scores contribute to adaptation beyond the impact of general resilience. To address these gaps, the factor structure, construct validity, and incremental validity of the PRS were assessed in exploratory factor analysis (EFA; 417 women, 134 men) and confirmatory factor analysis (CFA; 421 women, 135 men) samples of Chinese adults with chronic musculoskeletal pain who completed back-translated versions of the PRS and a battery of self-report measures previously validated in Chinese samples. A 2-factor, EFA-derived version of the PRS featuring a 7-item cognitive/affective positivity subscale and a 3-item behavioral perseverance subscale had the best overall fit from several hypothesized alternatives. Derived PRS subscales had significant moderate correlations with conceptually related measures and low correlations with conceptually less-related background characteristics, respectively. PRS subscale scores, particularly cognitive and affective positivity, accounted for significant unique variance in functioning independent of general resilience.