The journal of pain : official journal of the American Pain Society
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Morphine and other opioids are among the most effective prescription medications for the treatment of pain. Addiction and hyperalgesia associated with their long-term use limits the clinical utility of these drugs. In view of a role of somatodendritic serotonin-1A receptors in addiction and analgesic effects of morphine, the present study concerns effects of co-use of buspirone, a partial agonist at the serotonin-1A receptor, on reinforcing, hyperalgesic, and motor effects of morphine in rats. ⋯ These effects of repeated morphine administration were blocked in rats cotreated with buspirone. Pain perception was also slightly reduced in rats repeatedly treated with higher doses of buspirone. The findings are important for improving and extending therapeutic medications for pain.
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Review Meta Analysis
Is pain perception altered in people with depression? A systematic review and meta-analysis of experimental pain research.
Although clinical studies suggest depressed patients may be more vulnerable to pain, experimental research is equivocal. This meta-analysis aimed to clarify whether depression is associated with altered pain perception in response to noxious stimulation and to identify factors that might influence this association. A search of major electronic databases was conducted to identify experimental studies investigating pain response in depressed participants versus healthy control participants using established pain outcome measures. ⋯ However, considerable heterogeneity in the direction and magnitude of effects was observed, indicating a likely condition-specific effect of depression on pain. Subgroup analysis found that pain threshold/tolerance was increased in depression for exteroceptive (cutaneous) stimulation but decreased for interoceptive (ischemic) stimulation, but that substantial heterogeneity remained. Overall, results provide some support for altered pain processing in depression, but suggest this link is dependent upon modality and additional, unidentified factors.
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Evidence suggests that pain patients who report lifetime abuse experience greater psychological distress, have more severe pain and other physical symptoms, and greater functional disability. The aim of the present study was to determine the associations between a history of lifetime abuse and affective distress, fibromyalgianess (measured using the 2011 Fibromyalgia Survey), pain severity and interference, and physical functioning. A cross-sectional analysis of 3,081 individuals presenting with chronic pain was performed using validated measures and a history of abuse was assessed via patient self-report. ⋯ Mediation models showed that the Fibromyalgia Survey score and affective distress independently mediate the relationship between abuse and pain severity and physical functioning (Ps < .001). Our mediation models support a novel biopsychosocial paradigm wherein affective distress and fibromyalgianess interact to play significant roles in the association between abuse and pain. We posit that having a centralized pain phenotype underlies the mediation of increased pain morbidity in individuals with a history of abuse.
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Randomized Controlled Trial
Feasibility and Safety of a Virtual Reality Dodgeball Intervention for Chronic Low Back Pain: A Randomized Clinical Trial.
Whereas the fear-avoidance model of chronic low back pain (CLBP) posits a generic avoidance of movement that is perceived as threatening, we have repeatedly shown that individuals with high fear and CLBP specifically avoid flexion of the lumbar spine. Accordingly, we developed a virtual dodgeball intervention designed to elicit graded increases in lumbar spine flexion while reducing expectations of fear and harm by engaging participants in a competitive game that is entertaining and distracting. We recruited 52 participants (48% female) with CLBP and high fear of movement and randomized them to either a game group (n = 26) or a control group (n = 26). All participants completed a pregame baseline and a follow-up assessment (4-6 days later) of lumbar spine motion and expectations of pain and harm during standardized reaches to high (easier), middle, and low (hardest to reach) targets. For 3 consecutive days, participants in the game group completed 15 minutes of virtual dodgeball between baseline and follow-up. For the standardized reaching tests, there were no significant effects of group on changes in lumbar spine flexion, expected pain, or expected harm. However, virtual dodgeball was effective at increasing lumbar flexion within and across gameplay sessions. Participants reported strong positive endorsement of the game, no increases in medication use, pain, or disability, and no adverse events. Although these findings indicate that very brief exposure to this game did not translate to significant changes outside the game environment, this was not surprising because graded exposure therapy for fear of movement among individuals with low back pain typically last 8 to 12 sessions. Because of the demonstration of safety, feasibility, and ability to encourage lumbar flexion within gameplay, these findings provide support for a clinical trial wherein the treatment dose is more consistent with traditional graded exposure approaches to CLBP. ⋯ This study of a virtual reality dodgeball intervention provides evidence of feasibility, safety, and utility to encourage lumbar spine flexion among individuals with CLBP and high fear of movement.
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Codeine is a widely used opioid analgesic but studies on its misuse in chronic noncancer pain (CNCP) are still lacking. The aim of this study was to assess the incidence of codeine shopping behavior in CNCP patients and to identify the associated risk factors. This was a population-based retrospective cohort study from the French health insurance claims database from 2004 to 2014. ⋯ The 1-year incidence rate of codeine shopping behavior was 4.03% (95% confidence interval [CI], 3.07-5.28). In multivariate analysis, risk factors associated with shopping behavior were younger age (≤40 years) (hazard ratio [HR] = 7.29; 95% CI, 4.28-12.42), mental health disorders (HR = 2.25; 95% CI, 1.08-4.67), concurrent use of anxiolytic benzodiazepines (HR = 3.12; 95% CI, 1.55-6.26), and previous use of strong opioids (HR = 2.94; 95% CI, 1.24-6.98). The incidence of codeine shopping behavior in CNCP patients was 4% and risk factors identified were shared with those of opioid abuse.