Human Studies

The formation and persistence of negative pain-related expectations by classical conditioning remain incompletely understood. We elucidated behavioural and neural correlates involved in the acquisition and extinction of negative expectations towards different threats across sensory modalities. In two complementary functional magnetic resonance imaging studies in healthy humans, differential conditioning paradigms combined interoceptive visceral pain with somatic pain (study 1) and aversive tone (study 2) as exteroceptive threats. Conditioned responses to interoceptive threat predictors were enhanced in both studies, consistently involving the insula and cingulate cortex. Interoceptive threats had a greater impact on extinction efficacy, resulting in disruption of ongoing extinction (study 1), and selective resurgence of interoceptive CS-US associations after complete extinction (study 2). In the face of multiple threats, we preferentially learn, store, and remember interoceptive danger signals. As key mediators of nocebo effects, conditioned responses may be particularly relevant to clinical conditions involving disturbed interoception and chronic visceral pain.

The present study examined the role of attention control in understanding the development of negatively-biased pain memories as well as its moderating role in the relationship between pain catastrophizing and negatively-biased pain memories. Youth with chronic pain (N = 105) performed a cold pressor task (CPT) and completed self-report measures of state/trait pain catastrophizing and attention control, with the latter comprising both attention focusing and attention shifting. Two weeks after the CPT, youth's pain-related memories were elicited via telephone allowing to compute pain and anxiety memory bias indices (i.e., recalling pain intensity or pain-related anxiety, respectively, as higher than initially reported). Results indicated no main effects of attention control and pain catastrophizing on pain memories. However, both components of attention control (i.e., attention focusing and attention shifting) moderated the impact of pain catastrophizing on youth's memory bias, with opposite interaction effects. Specifically, whereas high levels of attention shifting buffered the influence of high pain catastrophizing on the development of pain memory bias, high levels of attention focusing strengthened the influence of high pain catastrophizing on the development of anxiety memory bias. Interaction effects were confined to trait catastrophizing (i.e., not state catastrophizing). Theoretical and clinical implications are discussed. PERSPECTIVE: This article investigates the role of attention control in the development of negatively-biased pain memories in children with chronic pain. Findings underscore the importance of targeting differential components of attention control and can inform intervention efforts to minimize the development of negatively biased pain memories in youth with chronic pain.

This study compared perceptions of the burden of patient care and associated clinical judgments between physicians and people with chronic pain (PWCP) in a 2 × 3 × 2 between-subjects design that varied participant type, patient-reported pain severity (4-6-8/10), and supporting medical evidence (low/high). 109 physicians and 476 American Chronic Pain Association members were randomly assigned to one of six conditions. Respondents estimated the clinical burden they would assume as the treating physician of a hypothetical patient with chronic low back pain, and made clinical judgments regarding that patient. Physician burden ratings were significantly higher than PWCP ratings, and clinical impressions (e.g., trust in pain report, medical attribution) and management concerns (e.g., opioid abuse risk) were relatively less favorable. Neither pain severity nor medical evidence affected burden ratings significantly. High medical evidence was associated with more favorable clinical impressions; higher pain severity led to more discounting of patient pain reports. Burden was significantly correlated with a range of clinical judgments. Results indicate that physicians and people with chronic pain differ in their perceptions of provider burden and related clinical judgments in ways that could impact treatment collaboration. Further research is needed that examines provider burden in actual clinical practice. Perspective Physicians and people with chronic pain (PWCP) estimated the clinical burden of patient care and made judgments about a hypothetical patient with chronic pain. Physician burden ratings were higher and clinical judgments less favorable, relative to PWCP respondents. These differences could impact treatment collaboration and merit study in clinical practice.

Tapering opioids for chronic pain can be challenging for both patients and prescribers, both of whom may be unsure of what to expect in terms of pain, distress, activity interference, and withdrawal symptoms over the first few weeks and months of the taper. In order to better prepare clinicians to provide patient-centred tapering support, the current research used prospective longitudinal qualitative methods to capture individual-level variation in patients' experience over the first few months of a voluntary physician-guided taper. The research aimed to identify patterns in individuals' experience of tapering, and explore whether patient characteristics, readiness to taper, opioid-tapering self-efficacy, or psychosocial context were related to tapering trajectory. Twenty-one patients with chronic non-cancer pain commencing tapering of long-term opioid therapy were recruited from a metropolitan tertiary pain clinic (n = 13) and a regional primary care practice (n = 8). Semi-structured phone interviews were conducted a mean of 8 times per participant over a mean duration of 12 weeks (N = 173). Four opioid tapering trajectories were identified, which we characterised as thriving, resilient, surviving, and distressed. High and low readiness to taper were a defining characteristic of "thriving" and "distressed" trajectories, respectively. Life adversity was a prominent theme of "resilient" and "distressed" trajectories, with supportive relationships buffering the effects of adversity for those who followed a "resilient" trajectory. Discussion focuses on the implications of these findings for the preparation and support of patients with chronic pain who are commencing opioid tapering.