Pain Catastrophizing Mediates the Association Between Mindfulness and Psychological Distress in Chronic Pain Syndrome.

AIM: Trait mindfulness has been found to be inversely associated with emotional distress such as depression and anxiety among patients suffering from pain. The current study investigated the putative mechanisms underlying these associations by examining whether pain catastrophizing mediates the association between mindfulness and psychological distress and whether this model differs in patients suffering from chronic pain compared to patients experiencing nonchronic pain in a medical rehabilitation setting. METHODS: Forty-eight patients in their subacute stage of recovery participated in the study. Seventeen participants had a diagnosis of chronic pain. Trait mindfulness was assessed using the Mindful Attention Awareness Scale, pain catastrophizing was assessed using the Pain Catastrophizing Scale, depression symptoms were assessed using the Patient Health Questionnaire, and anxiety was assessed using the Generalized Anxiety Disorder scale. Two mediation models were used, with pain catastrophizing mediating the association between mindfulness and depression and anxiety. RESULTS: Catastrophizing significantly mediated the association between trait mindfulness and depression (P < 0.05, confidence interval [CI] = -0.35, -0.05). Catastrophizing also mediated the relationship between trait mindfulness and anxiety (P < 0.05, CI = -0.34, -0.04). Two moderated mediation models were tested, in which pain catastrophizing fully mediated the relationship between trait mindfulness and depression and anxiety, but only in patients with chronic pain. CONCLUSIONS: The negative association between trait mindfulness and psychological distress may thus be partly attributed to pain catastrophizing: individuals high in trait mindfulness engage in less catastrophic thinking and therefore experience less distress. Importantly, this was only observed in the patients with chronic pain. These results further underscore the need to cope with pain catastrophizing and encourage mindfulness among patients with chronic pain.

Sensory modulation dysfunction is associated with Complex Regional Pain Syndrome.

OBJECTIVE: Complex Regional Pain Syndrome (CRPS), a chronic pain condition, develops mainly after limb trauma and severely inhibits function. While early diagnosis is essential, factors for CRPS onset are elusive. Therefore, identifying those at risk is crucial. Sensory modulation dysfunction (SMD), affects the capacity to regulate responses to sensory input in a graded and adaptive manner and was found associated with hyperalgesia in otherwise healthy individuals, suggestive of altered pain processing. AIM: To test SMD as a potential risk factor for CRPS. METHODS: In this cross-sectional study, forty-four individuals with CRPS (29.9±11 years, 27 men) and 204 healthy controls (27.4±3.7 years, 105 men) completed the Sensory Responsiveness Questionnaire-Intensity Scale (SRQ-IS). A physician conducted the CRPS Severity Score (CSS), testing individuals with CRPS. RESULTS: Thirty-four percent of the individuals with CRPS and twelve percent of the healthy individuals were identified to have SMD (χ2 (1) = 11.95; p<0.001). Logistic regression modeling revealed that the risk of CRPS is 2.68 and 8.21 times higher in individuals with sensory over- and sensory under-responsiveness, respectively, compared to non-SMD individuals (p = 0.03 and p = 0.01, respectively). CONCLUSIONS: SMD, particularly sensory under-responsiveness, might serve as a potential risk factor for CRPS and therefore screening for SMD is recommended. This study provides the risk index probability clinical tool a simple evaluation to be applied by clinicians in order to identify those at risk for CRPS immediately after injury. Further research is needed.