Marc O. Martel

Catastrophic thinking and heightened perception of pain in others

Abstract Past research has shown that pain catastrophizing contributes to heightened pain experience. The hypothesis advanced in this study was that individuals who score high on measures of pain catastrophizing would also perceive more intense pain in others. The study also examined the role of pain behaviour as a determinant of the relation between catastrophizing and estimates of others’ pain. To test the hypothesis, 60 undergraduates were asked to view videotapes of individuals taking part in a cold pressor procedure. Each individual in the videotapes was shown three times over the course of a 1 min immersion such that the same individual was observed experiencing different levels of pain. Correlational analyses revealed a significant positive correlation between levels of pain catastrophizing and inferred pain intensity, r = .31, p < .01. Follow‐up analyses indicated that catastrophizing was associated with a heightened propensity to rely on pain behaviour as a basis for drawing inferences about others‘ pain experience. Catastrophizing was associated with more accurate pain inferences on only one of three indices of inferential accuracy. The pattern of findings suggests that increasing reliance on pain behaviour as a means of inferring others’ pain will not necessarily yield more accurate estimates. Discussion addresses the processes that might underlie the propensity to attend more to others’ pain behaviour, and the clinical and interpersonal consequences of perceiving more pain in others.

Persistent pain in postmastectomy patients: comparison of psychophysical, medical, surgical, and psychosocial characteristics between patients with and without pain.

Summary Patients with and without persistent postmastectomy pain were tested. Psychosocial and psychophysical factors distinguished between groups more than demographic, surgical, and treatment‐related factors. Abstract Persistent postmastectomy pain (PPMP) is a major individual and public health problem. Increasingly, psychosocial factors such as anxiety and catastrophizing are being revealed as crucial contributors to individual differences in pain processing and outcomes. Furthermore, differences in patients’ responses to standardized quantitative sensory testing (QST) may aid in the discernment of who is at risk for acute and chronic pain after surgery. However, characterization of the variables that differentiate those with PPMP from those whose acute postoperative pain resolves is currently incomplete. The purpose of this study was to investigate important surgical, treatment‐related, demographic, psychophysical, and psychosocial factors associated with PPMP by comparing PPMP cases with PPMP‐free controls. Pain was assessed using the breast cancer pain questionnaire to determine the presence and extent of PPMP. Psychosocial and demographic information were gathered via phone interview, and women underwent a QST session. Consistent with most prior research, surgical and disease‐related variables did not differ significantly between cases and controls. Furthermore, treatment with radiation, chemotherapy, or hormone therapy was also not more common among those with PPMP. In contrast, women with PPMP did show elevated levels of distress‐related psychosocial factors such as anxiety, depression, catastrophizing, and somatization. Finally, QST in nonsurgical body areas revealed increased sensitivity to mechanical stimulation among PPMP cases, while thermal pain responses were not different between the groups. These findings suggest that an individual’s psychophysical and psychosocial profile may be more strongly related to PPMP than their surgical treatment.

Effects of testosterone replacement in men with opioid-induced androgen deficiency: A randomized controlled trial

Abstract Symptomatic androgen deficiency is common in patients taking opioid analgesics, as these drugs potently suppress the hypothalamic–pituitary–gonadal axis. However, the efficacy of testosterone replacement in this setting remains unclear. The objective of this trial was to evaluate the efficacy of testosterone replacement on pain perception and other androgen-dependent outcomes in men with opioid-induced androgen deficiency. We conducted a randomized, double-blind, parallel placebo-controlled trial at an outpatient academic research center. Participants were men aged 18 to 64 years on opioid analgesics for chronic noncancer pain, and total testosterone levels were <350 ng/dL. Participants were randomly assigned to 14 weeks of daily transdermal gel that contained 5 g of testosterone or placebo. Primary outcomes were changes in self-reported clinical pain and objectively assessed pain sensitivity. Sexual function, quality of life, and body composition were also assessed. The mean age was 49 years. The median total and free testosterone levels at baseline were 243 ng/dL and 47 pg/mL and 251 ng/dL and 43 pg/mL in the testosterone and placebo arm, respectively. Of the 84 randomized participants, 65 had follow-up data on efficacy outcomes. Compared with men assigned to the placebo arm, those assigned to testosterone replacement experienced greater improvements in pressure and mechanical hyperalgesia, sexual desire, and role limitation due to emotional problems. Testosterone administration was also associated with an improvement in body composition. There were no between-group differences in changes in self-reported pain. In conclusion, in men with opioid-induced androgen deficiency, testosterone administration improved pain sensitivity, sexual desire, body composition, and aspects of quality of life.

The multilevel organization of vicarious pain responses: Effects of pain cues and empathy traits on spinal nociception and acute pain

&NA; The shared‐representation model of empathy suggests that vicarious pain processes rely partly on the activation of brain systems underlying self‐pain in the observer. Here, we tested the hypothesis that self‐pain may be facilitated by the vicarious priming of neural systems underlying pain perception. Pictures illustrating painful agents applied to the hand or the foot (sensory information), or painful facial expressions (emotional information) were shown to 43 participants to test the effects of vicarious pain on the nociceptive flexion reflex (NFR) of the lower limb and pain intensity and unpleasantness produced by transcutaneous electrical stimulation applied over the sural nerve. Results confirmed the expected priming effects of vicarious pain on spinal and perceptual processes. However, for comparable pain intensity and arousal evoked by the pain pictures, the facilitation of the NFR and the self‐pain unpleasantness measurements was more robust in response to pictures depicting pain sensory compared to emotional information. Furthermore, the facilitation of the NFR by pain pictures was positively correlated with the empathy trait of the observer. In contrast, the change in perceived shock‐pain intensity was negatively correlated with empathic traits. This dissociation implies that low‐level vicarious priming processes underlying pain facilitation may be downregulated at higher pain‐processing stages in individuals reporting higher levels of empathy. We speculate that this process contributes to reducing self–other assimilation and is necessary to adopt higher‐order empathic responses and altruistic behaviors. A priming effect of vicarious pain and individuals’ empathic traits on self‐pain processing at different levels of the neuraxis is revealed.

Sex Differences in the Stability of Conditioned Pain Modulation (CPM) among Patients with Chronic Pain

OBJECTIVES To examine the temporal stability of conditioned pain modulation (CPM), formerly termed diffuse noxious inhibitory controls, among a sample of patients with chronic pain. The study also examined the factors that might be responsible for the stability of CPM. DESIGN, SUBJECTS, AND METHODS In this test-retest study, patients underwent a series of standardized psychophysical pain-testing procedures designed to assess CPM on two separate occasions (i.e., baseline and follow up). Patients also completed self-report measures of catastrophizing (Pain Catastrophizing Scale [PCS] and negative affect [NA]). RESULTS Overall, results provided evidence for the stability of CPM among patients with chronic pain. Results, however, revealed considerable sex differences in the stability of CPM. For women, results revealed a significant test-retest correlation between baseline and follow-up CPM scores. For men, however, the test-retest correlation between baseline and follow-up CPM scores was not significant. Results of a Fishers Z-test revealed that the stability of CPM was significantly greater for women than for men. Follow-up analyses revealed that the difference between men and women in the stability of CPM could not be accounted for by any demographic (e.g., age) and/or psychological factors (PCS and NA). CONCLUSIONS Our findings suggest that CPM paradigms possess sufficient reliability to be incorporated into bedside clinical evaluation of patients with chronic pain, but only among women. The lack of CPM reproducibility/stability observed among men places limits on the potential use of CPM paradigms in clinical settings for the assessment of mens endogenous pain-inhibitory function.

The persistence of pain behaviors in patients with chronic back pain is independent of pain and psychological factors

&NA; The primary purpose of the present study was to examine the temporal stability of communicative and protective pain behaviors in patients with chronic back pain. The study also examined whether the stability of pain behaviors could be accounted for by patients’ levels of pain severity, catastrophizing, or fear of movement. Patients (n = 70) were filmed on two separate occasions (i.e., baseline, follow‐up) while performing a standardized lifting task designed to elicit pain behaviors. Consistent with previous studies, the results provided evidence for the stability of pain behaviors in patients with chronic pain. The analyses indicated that communicative and protective pain behavior scores did not change significantly from baseline to follow‐up. In addition, significant test–retest correlations were found between baseline and follow‐up pain behavior scores. The results of hierarchical multiple regression analyses further showed that pain behaviors remained stable over time even when accounting for patients’ levels of pain severity. Regression analyses also showed that pain behaviors remained stable when accounting for patients’ levels of catastrophizing and fear of movement. Discussion addresses the potential contribution of central neural mechanisms and social environmental reinforcement contingencies to the stability of pain behaviors. The discussion also addresses how treatment interventions specifically aimed at targeting pain behaviors might help to augment the overall impact of pain and disability management programs.

Patients who display protective pain behaviors are viewed as less likable, less dependable, and less likely to return to work.

Summary The expression of protective pain behaviors might contribute to the development and maintenance of occupational disability by influencing clinicians’ judgments about patients’ readiness to work. Abstract In the present study, participants (ie, observers) watched video sequences of patients with chronic back pain performing a physically demanding lifting task. Participants were asked to make judgments about patients’ levels of pain and readiness to work. For each patient, observers were also asked to make judgments about personality traits relevant to work performance and employment. The primary objective of this study was to examine the differential influence of communicative and protective pain behaviors on observers’ judgments about patients’ pain intensity and readiness to work. Consistent with previous research, analyses indicated that patients displaying either communicative (eg, facial expressions) or protective (eg, guarding) pain behaviors were perceived as having significantly more pain than patients displaying no pain behavior. Analyses also revealed that patients displaying protective pain behaviors were perceived as being significantly less likable, less dependable, and less ready to work than patients displaying other forms of pain behavior. Discussion addresses the processes by which pain behaviors might influence observers’ judgments about patients’ personality traits and readiness to work. Implications of the present findings for clinical practice and the management of patients presenting with pain conditions are also discussed.

Contextual determinants of pain judgments

Abstract The objective of this study was to examine the influence of variations in contextual features of a physically demanding lifting task on the judgments of others’ pain. Healthy undergraduates (n = 98) were asked to estimate the pain experience of chronic pain patients who were filmed while lifting canisters at different distances from their body. Of interest was whether contextual information (i.e., lifting posture) contributed to pain estimates beyond the variance accounted for by pain behavior. Results indicated that the judgments of others’ pain varied significantly as a function of the contextual features of the pain‐eliciting task; observers estimated significantly more pain when watching patients lifting canisters positioned further away from the body than canisters closest from the body. Canister position contributed significant unique variance to the prediction of pain estimates even after controlling for observers’ use of pain behavior as a basis of pain estimates. Correlational analyses revealed that greater use of the contextual features when judging others’ pain was related to a lower discrepancy (higher accuracy) between estimated and self‐reported pain ratings. Results also indicated that observers’ level of catastrophizing was associated with more accurate pain estimates. The results of a regression analysis further showed that observers’ level of catastrophizing contributed to the prediction of the accuracy of pain estimates over and above the variance accounted for by the utilisation of contextual features. Discussion addresses the processes that might underlie the utilisation of contextual features of a pain‐eliciting task when estimating others’ pain.

Distraction analgesia in chronic pain patients: the impact of catastrophizing.

Background:Diverting attention away from noxious stimulation (i.e., distraction) is a common pain-coping strategy. Its effects are variable across individuals, however, and the authors hypothesized that chronic pain patients who reported higher levels of pain catastrophizing would derive less pain-reducing benefit from distraction. Methods:Chronic pain patients (n = 149) underwent psychometric and quantitative sensory testing, including assessment of the temporal summation of pain in the presence and absence of a distracting motor task. Results:A simple distraction task decreased temporal summation of pain overall, but, surprisingly, a greater distraction analgesia was observed in high catastrophizers. This enhanced distraction analgesia in high catastrophizers was not altered when controlling for current pain scores, depression, anxiety, or opioid use (analysis of covariance [ANCOVA]: F = 8.7, P < 0.005). Interestingly, the magnitude of distraction analgesia was inversely correlated with conditioned pain modulation (Pearson R = −0.23, P = 0.005). Conclusion:Distraction produced greater analgesia among chronic pain patients with higher catastrophizing, suggesting that catastrophizing’s pain-amplifying effects may be due in part to greater attention to pain, and these patients may benefit from distraction-based pain management approaches. Furthermore, these data suggest that distraction analgesia and conditioned pain modulation may involve separate underlying mechanisms.

Distress Intolerance and Prescription Opioid Misuse Among Patients With Chronic Pain

UNLABELLED The risk for misuse of opioid medications is a significant challenge in the management of chronic pain. The identification of those who may be at greater risk for misusing opioids is needed to facilitate closer monitoring of high-risk subgroups, and may help to identify therapeutic targets for mitigating this risk. The aim of this study was to examine whether distress intolerance-the perceived or actual inability to manage negative emotional and somatic states-was associated with opioid misuse in those with chronic pain. A sample of 51 participants prescribed opioid analgesics for chronic back or neck pain were recruited for a 1-time laboratory study. Participants completed measures of distress intolerance and opioid misuse, and a quantitative sensory testing battery. Results suggested that distress intolerance was associated with opioid misuse, even controlling for pain severity and negative affect. Distress intolerance was not associated with pain severity, threshold, or tolerance, but was associated with self-reported anxiety and stress after noxious stimuli. This study found robust differences in distress intolerance between adults with chronic pain with and without opioid medication misuse. Distress intolerance may be a relevant marker of risk for opioid misuse among those with chronic pain. PERSPECTIVE This study demonstrated that distress intolerance was associated with opioid misuse in adults with chronic pain who were prescribed opioids. Distress intolerance can be modified with treatment, and thus may be relevant not only for identification of risk for opioid misuse, but also for mitigation of this risk.