Pain catastrophizing is prominent in chronic pain conditions such as fibromyalgia and has been proposed to contribute to the development of pain widespreadness. However, the brain mechanisms responsible for this association are unknown. We hypothesized that increased resting salience network (SLN) connectivity to nodes of the default mode network (DMN), representing previously reported pain-linked cross-network enmeshment, would be associated with increased pain catastrophizing and widespreadness across body sites. We applied functional magnetic resonance imaging (fMRI) and digital pain drawings (free-hand drawing over a body outline, analyzed using conventional software for multivoxel fMRI analysis) to investigate precisely quantified measures of pain widespreadness and the associations between pain catastrophizing (Pain Catastrophizing Scale), resting brain network connectivity (Dual-regression Independent Component Analysis, 6-minute multiband accelerated fMRI), and pain widespreadness in fibromyalgia patients (N = 79). Fibromyalgia patients reported pain in multiple body areas (most frequently the spinal region, from the lower back to the neck), with moderately high pain widespreadness (mean ± SD: 26.1 ± 24.1% of total body area), and high pain catastrophizing scale scores (27.0 ± 21.9, scale range: 0-52), which were positively correlated (r = 0.26, P = 0.02). A whole-brain regression analysis focused on SLN connectivity indicated that pain widespreadness was also positively associated with SLN connectivity to the posterior cingulate cortex, a key node of the DMN. Moreover, we found that SLN-posterior cingulate cortex connectivity statistically mediated the association between pain catastrophizing and pain widespreadness (P = 0.01). In conclusion, we identified a putative brain mechanism underpinning the association between greater pain catastrophizing and a larger spatial extent of body pain in fibromyalgia, implicating a role for brain SLN-DMN cross-network enmeshment in mediating this association.

Objective: To examine the role of several interrelated, potentially modifiable psychological factors (i.e., mindfulness and catastrophizing) in influencing patient-reported functioning. Methods: In this cross-sectional study, 107 patients with fibromyalgia completed self-report assessments of pain severity, functioning and impact of symptoms, mindfulness, and pain catastrophizing. Linear regression and bootstrapping mediation analyses were performed to assess the relationships between these factors. Results: Pain intensity was significantly and positively associated with pain catastrophizing and impact of fibromyalgia on functioning. Linear regression analyses indicated that pain intensity, catastrophizing, and mindfulness affect functioning in fibromyalgia. Follow-up mediation analysis revealed a significant indirect effect of pain catastrophizing on the relationship between pain intensity and fibromyalgia functioning. Conclusion: Individuals with fibromyalgia who have higher levels of pain and catastrophizing, and lower levels of mindfulness, are more likely to experience impaired functioning. Our findings suggest that pain catastrophizing appears to be an especially important variable contributing to reduced functioning in women with fibromyalgia. Therefore, catastrophizing-reducing treatments (e.g., cognitive behavioral therapy) are likely to have direct, beneficial impacts on functioning.

Objective The objective was to perform a systematic review and meta-analysis of the literature on the effects of buprenorphine on chronic pain outcomes (i.e., patient-reported pain intensity) in patients with and without opioid use disorder (OUD). Design Ovid/Medline, PubMed, Embase, and the Cochrane Library were searched for studies that explored the effectiveness (in reducing pain) of buprenorphine treatment for chronic pain patients with and without a history of OUD. Randomized controlled trials and observational studies were included in the review. Methods Two separate searches were conducted to identify buprenorphine trials that included chronic pain patients either with or without OUD. Five studies used validated pain report measures and included a chronic pain population with OUD. Nine studies used validated report measures and included chronic pain patients without OUD. Meta-analysis was performed using the R, version 3.2.2, Metafor package, version 1.9–7. Results The meta-analysis revealed that buprenorphine has a beneficial effect on pain intensity overall, with a small mean effect size in patients with comorbid chronic pain and OUD and a moderate- to large-sized effect in chronic pain patients without OUD. Conclusions Our results indicate that buprenorphine is modestly beneficial in reducing pain intensity in patients without OUD. Although informative, these findings should be carefully interpreted due to the small amount of data available and the variation in study designs.