Perceived control over anxiety-related events as a predictor of pain behaviors in a cold pressor task

Bystander Acknowledgment Mitigates the Psychological and Physiological Pain of Racial Discrimination for Black Young Adults: A Randomized Controlled Trial

Racism increases pain sensitization and contributes to racialized pain inequities; however, research has not tested interventions targeting racism to reduce pain. In this study, we examined whether White bystanders can act to mitigate racism's pain-sensitizing effects. To simulate racial exclusion in the laboratory, Black young adults (age 18-30; N = 92) were randomly assigned to be included or excluded by White players in a ball-tossing game (Cyberball). For half of the excluded participants, White bystanders acknowledged and apologized for the racial exclusion. Participants completed a cold pressor task to assess pain threshold, tolerance, and unpleasantness, and completed a survey assessing psychological needs (ie, belongingness, self-esteem, meaningful existence, and self-control). Participants who experienced racial exclusion reported significantly more threatened psychological needs and increased laboratory pain sensitization (ie, lower pain threshold and tolerance) than those who were included. However, when a White bystander acknowledged the racism, excluded participants reported higher levels of self-control, self-esteem, and decreased pain sensitization (pain threshold and tolerance) relative to excluded participants whose experience was not acknowledged. Our findings support that racism increased Black people's pain sensitivity and provide initial evidence for White bystander acknowledgment as a health intervention. PERSPECTIVE: Continual exposure to racism likely contributes to inequities in pain sensitization. We demonstrate that acute exposure to mild racism increases acute pain sensitization. Results suggest that a bystander acknowledging witnessed racism can buffer the acute sensitizing effects of racism on pain, pointing to the potential of interpersonal interventions targeting racism. TRIAL REGISTRATION: Clinicaltrials.gov NCT06113926.

Pain sensitivity as a state marker and predictor for adolescent non-suicidal self-injury

BACKGROUND

The pain analgesia hypothesis suggests that reduced pain sensitivity (PS) is a specific risk factor for the engagement in non-suicidal self-injury (NSSI). Consistent with this, several studies found reduced PS in adults as well as adolescents with NSSI. Cross-sectional studies in adults with borderline personality disorder (BPD) suggest that PS may (partially) normalize after remission or reduction of BPD symptoms. The objective of the present study was to investigate the development of PS over 1 year in a sample of adolescents with NSSI and to investigate whether PS at baseline predicts longitudinal change in NSSI.

METHODS

N = 66 adolescents who underwent specialized treatment for NSSI disorder participated in baseline and 1-year follow-up assessments, including heat pain stimulation for the measurement of pain threshold and tolerance. Associations between PS and NSSI as well as BPD and depressive symptoms were examined using negative binomial, logistic, and linear regression analyses.

RESULTS

We found that a decrease in pain threshold over time was associated with reduced NSSI (incident rate ratio = 2.04, p = 0.047) and that higher pain tolerance at baseline predicted lower probability for NSSI (odds ratio = 0.42, p = 0.016) 1 year later. However, the latter effect did not survive Holm correction (p = 0.059). No associations between PS and BPD or depressive symptoms were observed.

CONCLUSION

Our findings suggest that pain threshold might normalize with a decrease in NSSI frequency and could thus serve as a state marker for NSSI.

Reduced Spinal Cord Gray Matter in Patients with Fibromyalgia Using Opioids Long-term

Objective

Chronic pain involves alterations in brain gray matter volume (GMV). Moreover, opioid medications are known to reduce GMV in numerous brain regions involved in pain processing. However, no research has evaluated (1) chronic pain-related GMV alterations in the spinal cord or (2) the effect of opioids on spinal cord GMV. Accordingly, this study evaluated spinal cord GMV in health controls and patients with fibromyalgia who were using and not using opioids long-term.

Methods

We analyzed average C5 - C7 GMV of the spinal cord dorsal and ventral horns in separate female cohorts of healthy controls (HC, n = 30), fibromyalgia patients not using opioids (FMN, n = 31), and fibromyalgia patients using opioids long-term (FMO, n = 27). To assess the effect of group on average dorsal and ventral horn GMV, we conducted a one-way multivariate analysis of covariance.

Results

After controlling for age, we observed a significant effect of group on ventral horn GMV (p = 0.03, η2 = 0.09), and on dorsal horn GMV (p = 0.05, η2 = 0.08). Tukey's posthoc comparisons showed that, compared to HC participants, FMOs had significantly lower ventral (p = 0.01) and dorsal (p = 0.02) GMVs. Among FMOs only, ventral horn GMV was significantly positively associated with pain severity and interference, and both dorsal and ventral GMVs were significantly positively associated with cold pain tolerance.

Conclusion

Long-term opioid use may impact sensory processing in fibromyalgia via gray matter changes within the cervical spinal cord.

Evidence for a Behaviourally Measurable Perseverance Trait in Humans

The aim was to create and study a possible behavioural measure for trait(s) in humans that reflect the ability and motivation to continue an unpleasant behaviour, i.e., behavioural perseverance or persistence (BP). We utilised six different tasks with 54 subjects to measure the possible BP trait(s): cold pressor task, hand grip endurance task, impossible anagram task, impossible verbal reasoning task, thread and needle task, and boring video task. The task performances formed two BP factors. Together, the two-factor solution is responsible for the common variance constituting 37.3% of the total variance in the performances i.e., performance times. Excluding the impossible anagram task, the performance in any given task was better explained by performances in the other tasks (i.e., “trait”, η² range = 0.131–0.253) than by the rank order variable (“depletion”, i.e., getting tired from the previous tasks, η2 range = 0–0.096).

The Cold Pressor Test as a Predictor of Prolonged Postoperative Pain, a Prospective Cohort Study

INTRODUCTION

Presently, it is difficult to predict which patients are at increased risk of ongoing pain problems postoperatively. This study followed a group of patients from the week before their operation until 3 months after it, to identify potential risk variables.

METHODS

Fifty-four patients undergoing moderate-major gynaecological surgery at Christchurch Women's Hospital were recruited and assessed preoperatively over an 11-week period. At this initial assessment, participants were subjected to a cold pressor test (CPT). Telephonic follow-up was conducted at 6 weeks and 3 months postoperatively, to determine pain status. Information regarding the type of operation and surgical approach was collected from hospital records.

RESULTS

Pain threshold (time taken to report the onset of pain), as measured by the CPT, was significantly predictive of prolonged pain outcomes (area under the curve = 0.80, 95 % CI 0.66, 0.95). Pain tolerance (total time taken to end the CPT voluntarily) was similarly predictive but non-significant (area under the curve = 0.69, 95 % CI 0.47, 0.90).

CONCLUSION

The preoperative cold pressor test shows some promise for predicting ongoing postoperative pain. However, more research is needed to determine the clinical significance of these findings in larger samples and how they could be incorporated into clinical practice.

A Video Game Promoting Cancer Risk Perception and Information Seeking Behavior Among Young-Adult College Students: A Randomized Controlled Trial

Background

Risky behaviors tend to increase drastically during the transition into young adulthood. This increase may ultimately facilitate the initiation of carcinogenic processes at a young age, highlighting a serious public health problem. By promoting information seeking behavior (ISB), young adults may become aware of cancer risks and potentially take preventive measures.

Objective

Based on the protection motivation theory, the current study seeks to evaluate the impact of challenge in a fully automated video game called Re-Mission on young adult college students' tendency to perceive the severity of cancer, feel susceptible to cancer, and engage in ISB.

Methods

A total of 216 young adults were recruited from a university campus, consented, screened, and randomized in a single-blinded format to 1 of 3 conditions: an intervention group playing Re-Mission at high challenge (HC; n=85), an intervention group playing Re-Mission at low challenge (LC; n=81), and a control group with no challenge (NC; presented with illustrated pictures of Re-Mission; n=50). Measurement was conducted at baseline, immediate posttest, 10-day follow-up, and 20-day follow-up. Repeated-measures mixed-effect models were conducted for data analysis of the main outcomes.

Results

A total of 101 young adults continued until 20-day follow-up. Mixed-effect models showed that participants in the HC and LC groups were more likely to increase in perceived susceptibility to cancer (P=.03), perceived severity of cancer (P=.02), and ISB (P=.01) than participants in the NC group. The LC group took until 10-day follow-up to show increase in perceived susceptibility (B=0.47, standard error (SE) 0.16, P=.005). The HC group showed an immediate increase in perceived susceptibility at posttest (B=0.43, SE 0.14, P=.002). The LC group exhibited no changes in perceived severity (B=0.40, SE 0.33, P=.24). On the other hand, the HC group showed a significant increase from baseline to posttest (B=0.39, SE 0.14, P=.005), maintaining this increase until 20-day follow-up (B=−0.007, SE 0.26, P=.98). Further analyses indicated that perceived threat from virtual cancer cells in the game is related to the increase in perceived severity (B=0.1, SE 0.03, P=.001), and perceived susceptibility is related to changes in ISB at 10-day follow-up (B=0.21, SE 0.08, P=.008).

Conclusions

The feature of challenge with cancer cells in a virtual environment has the potential to increase cancer risk perception and ISB. The results are promising considering that the Re-Mission intervention was neither designed for cancer risk communication, nor applied among healthy individuals. Further research is needed to understand the theoretical framework underlying the effects of Re-Mission on ISB. The findings call for the development of a Web-based, game-based intervention for cancer risk communication and information seeking among young adults.

ClinicalTrial

International Standard Randomized Controlled Trial Number (ISRCTN): 15789289; http://www.controlled-trials.com/ISRCTN15789289 (Archived by WebCite at http://www.webcitation.org/6jGYZC3lZ)

Pain analgesia among adolescent self-injurers

Although non-suicidal self-injury (NSSI) involves self-inflicted physical harm, many self-injurers report feeling little or no pain during the act. Here we test: (1) whether the pain analgesia effects observed among adult self-injurers are also present among adolescents, and (2) three potential explanatory models proposing that habituation, dissociation, and/or self-criticism help explain the association between NSSI and pain analgesia among adolescents. Participants were 79 adolescents (12-19 years) recruited from the community who took part in a laboratory-based pain study. Results revealed that adolescent self-injurers have a higher pain threshold and greater pain endurance than non-injurers. Statistical mediation models revealed that the habituation and dissociation models were not supported; however, a self-critical style does mediate the association between NSSI and pain analgesia. The present findings extend earlier work by highlighting that a self-critical style may help to explain why self-injurers exhibit pain analgesia. Specifically, the tendency to experience self-critical thoughts in response to stressful events may represent a third variable that increases the likelihood of both NSSI and pain analgesia. Prospective experimental studies are needed to replicate and tease apart the direction of these associations, and may provide valuable leads in the development of effective treatments for this dangerous behavior problem.

Autonomic arousal and experimentally induced pain: a critical review of the literature

BACKGROUND

Autonomic arousal frequently is assumed to be a component of the pain response, perhaps because physiological mechanisms connecting pain and autonomic reactivity can be easily conceptualized. The evidence clarifying autonomic responses specific to painful stimulation, however, has been rather sporadic and lacks coherence; thus, a summary and critical review is needed in this area.

OBJECTIVES

To summarize and integrate findings from 39 experimental investigations from 1970 to 2012 of pain-induced autonomic arousal in humans.

METHODS

Medline and PsycINFO databases were searched for relevant articles. References from these articles were also considered for review.

RESULTS

Painful stimuli increase respiration rate, induce muscle tension, intensify electrodermal activity and dilate the pupils. Cardiovascular activity also increases, but the pattern displayed in response to pain is complex; peripheral vasoconstriction and sympathetically mediated cardiac responses are most typical. Additionally, autonomic expression of pain shows inconsistent relations with verbal and overt motor responses.

CONCLUSIONS

Autonomic arousal can be legitimately measured and modified as one facet of the pain response. Future research should particularly focus on increasing sample size and broadening the diversity of participants. To improve the ability to compare and contrast findings across studies, as well as to increase the applicability of laboratory findings to naturalistic pain, investigators also must enhance experimental design by increasing uniformity or accounting for differences in methodology. Finally, further work remains to utilize more specific assessments of autonomic response and to assess relationships of autonomic reactivity with other cognitive (e.g., attention) and affective (e.g., anxiety) variables.

Computer-delivered social norm message increases pain tolerance

BACKGROUND

Few experimental studies have been conducted on social determinants of pain tolerance.

PURPOSE

This study tests a brief, computer-delivered social norm message for increasing pain tolerance.

METHODS

Healthy young adults (N = 260; 44 % Caucasian; 27 % Hispanic) were randomly assigned into a 2 (social norm) × 2 (challenge) cold pressor study, stratified by gender. They received standard instructions or standard instructions plus a message that contained artificially elevated information about typical performance of others.

RESULTS

Those receiving a social norm message displayed significantly higher pain tolerance, F(1, 255) = 26.95, p < .001, η p (2)  = .10 and pain threshold F(1, 244) = 9.81, p = .002, η p (2)  = .04, but comparable pain intensity, p > .05. There were no interactions between condition and gender on any outcome variables, p > .05.

CONCLUSIONS

Social norms can significantly increase pain tolerance, even with a brief verbal message delivered by a video.

Angstbezogenes Kontrollerleben

Theoretischer Hintergrund: Subjektive Kontrollüberzeugungen werden als wesentlicher Faktor in der Entstehung und Aufrechterhaltung von Angststörungen diskutiert. Der Angstkontrollfragebogen (AKF) stellt das einzige Verfahren dar, das auf die Erfassung angstspezifischer Kontrollüberzeugungen zielt. Fragestellung: Wie ist die psychometrische Güte einer deutschen Übersetzung des AKF zu beurteilen? Methode: Untersuchung des AKF in einer nicht-klinischen und einer klinischen Stichprobe. Ergebnisse: Der AKF Gesamtscore wies befriedigende Reliabilitätskennwerte auf; darüber hinaus wurden Hinweise auf konvergente Validität gefunden. Allerdings stellen die Ergebnisse die Spezifität des Verfahrens für Angsterleben in Frage. Wie bereits in Studien zur Originalversion konnte keine überzeugende Faktorenstruktur etabliert werden. Schlussfolgerungen: Der AKF stellt eine potentiell wichtige Ergänzung nicht-symptomspezifischer Maße zur Erklärung von Psychopathologie dar, bedarf jedoch insbesondere hinsichtlich seiner latenten Struktur weiterer Überprüfung.

The influence of perceived control and self-efficacy on the sensory evaluation of experimentally induced pain

BACKGROUND AND AIMS

Prior research has demonstrated the role of perceived control and self-efficacy beliefs over pain in reducing pain and pain-related disability. The present study aimed to examine the independent influence of perceived control and self-efficacy beliefs on the subjective evaluation of pain.

METHODS

Healthy participants (N = 79) were randomly assigned to one of four conditions that were formed by manipulations of perceived control and self-efficacy. At two occasions in the experimental procedure pain was induced by means of electrical stimulation (16 s) to the lower forearm. Prior to and following upon each pain stimulus, participants completed ratings of pain intensity and pain unpleasantness.

RESULTS

High self-efficacy regarding the ability to exert control over pain resulted in a significant reduction in anticipated pain intensity, anticipated pain unpleasantness, and experienced pain intensity ratings. Furthermore, anticipated pain intensity was found to mediate the relation between self-efficacy and experienced pain intensity.

CONCLUSIONS

It is concluded that in order to observe beneficial effects of offering control over pain, it is important that individuals are convinced (i.e. have high self-efficacy) that they are able to exert this control successfully.

The influence of fear of symptoms and perceived control on asthma symptom perception

OBJECTIVE

Self-reported asthma symptoms correlate only modestly with measures of underlying pathophysiological mechanisms. In this study, we investigated the role of fear of symptoms and perceived control on respiratory symptom perception in patients with asthma.

METHODS

Patients with intermittent to moderate persistent asthma (N=32) were administered 4 subsequent rebreathing challenges (one using 100% O(2) and three using 5% CO(2) and 95% O(2)). We manipulated perceived control by providing information on the availability/unavailability of rescue medication during the challenges (perceived control/no control condition). Perceived symptoms and lung function were assessed after each rebreathing challenge.

RESULTS

Persons with low fear of symptoms reported respiratory symptoms to be less unpleasant during the perceived control condition compared to the no control condition. The reverse was found for persons with high fear of symptoms. The interaction between fear of symptoms and the control manipulations was mediated by threat perception.

CONCLUSION

Messages intended to increase perceived control over symptoms may actually increase threat in persons with high fear of symptoms and eventually increase unpleasantness of respiratory sensations. This finding underlines the importance of affective processes in the perception of asthma symptoms and shows that instructions to patients should take pre-existing fear levels into account.

Does intolerance of uncertainty predict anticipatory startle responses to uncertain threat?

Intolerance of uncertainty (IU) has been proposed to be an important maintaining factor in several anxiety disorders, including generalized anxiety disorder, obsessive-compulsive disorder, and social phobia. While IU has been shown to predict subjective ratings and decision-making during uncertain/ambiguous situations, few studies have examined whether IU also predicts emotional responding to uncertain threat. The present study examined whether IU predicted aversive responding (startle and subjective ratings) during the anticipation of temporally uncertain shocks. Sixty-nine participants completed three experimental conditions during which they received: no shocks, temporally certain/predictable shocks, and temporally uncertain shocks. Results indicated that IU was negatively associated with startle during the uncertain threat condition in that those with higher IU had a smaller startle response. IU was also only related to startle during the uncertain (and not the certain/predictable) threat condition, suggesting that it was not predictive of general aversive responding, but specific to responses to uncertain aversiveness. Perceived control over anxiety-related events mediated the relation between IU and startle to uncertain threat, such that high IU led to lowered perceived control, which in turn led to a smaller startle response. We discuss several potential explanations for these findings, including the inhibitory qualities of IU. Overall, our results suggest that IU is associated with attenuated aversive responding to uncertain threat.

Relations among perceived control over anxiety-related events, worry, and generalized anxiety disorder in a sample of adolescents

This study examined the associations among perceived control over anxiety-related events, worry, and both symptoms and diagnoses of generalized anxiety disorder (GAD). The sample was comprised of 140 adolescents (60 girls) between the ages of 10 and 17 years (M ( age ) = 14.6 years; SD = 2.25) recruited from the general community. Findings were consistent with hypotheses. Self-reported perceived control over anxiety-related events related negatively to worry as well as symptoms and diagnoses of GAD even after accounting for variance associated with age, gender, and negative affectivity. Results are discussed in terms of the theoretical implications that perceived control over anxiety-related events may have for understanding GAD symptomatology among youth.

Factorial Structure of the Anxiety Control Questionnaire in Chinese Adolescents

This article examines the psychometric structure of the Anxiety Control Questionnaire (ACQ) in Chinese adolescents. With the data collected from 212 senior high school students (94 females, 110 males, 8 unknown), seven models are tested using confirmatory factor analyses in the framework of the multitrait—multimethod strategy. Results indicate that the structure of the ACQ based on Chinese adolescents data is different from the one proposed by R. M. Rapee, M. G. Craske, T. A. Brown, and D. H. Barlow (1996). Method effects are found and the ACQ is organized according to three factors, one substantive factor and two method factors associated with the positive- and negative-worded items, respectively. The implication of the method effect is discussed.

Use of pain threshold reports to satisfy social needs

OBJECTIVE

To examine the hypothesis that experimental threats to social belongingness, interacting with individual differences in attachment security, cause modification of pain threshold reports by individuals who report high pain thresholds at baseline.

METHODS

In each of three studies, baseline pain threshold and tolerance were assessed in response to a pain task (cold pressor pain in Studies 1 and 2, finger pressure pain in Study 3). Participants then completed a measure of attachment security and were randomly assigned to a social exclusion or control condition (exclusion from a computer game in Study 1, recalling past rejection experiences in Studies 2 and 3). The pain task was administered again to examine the effects on pain threshold and tolerance.

RESULTS

Those with high anxious attachment and high baseline pain thresholds reported higher postmanipulation pain thresholds in the exclusion conditions than in the control conditions. Those with low anxious attachment and high baseline pain thresholds reported lower postmanipulation pain thresholds in the exclusion conditions than in the control conditions. No differences were found for pain tolerance.

CONCLUSIONS

Across studies, results suggested that postmanipulation pain threshold reports of individuals with high baseline pain thresholds were particularly responsive to social exclusion. The form of the response was dependent on the level of anxious attachment. The present studies provide evidence that variance in pain threshold reports not accounted for by pain intensity may reflect the use of pain reports to satisfy social needs. This work also suggests that baseline measures of pain thresholds may, in interaction with psychological variables, have predictive power beyond serving as a control variable.

Predictors of wrist function and health status after operative treatment of fractures of the distal radius

PURPOSE

To identify the most important determinants of physician-based and patient-based scoring systems for the wrist and upper extremity after operative treatment of a fracture of the distal radius, with the hypothesis that pain is the strongest determinant of both types of scores.

METHODS

Eighty-four patients were evaluated a minimum of 6 months after operative fixation of an unstable distal radius fracture using 2 physician-based evaluation instruments (the Mayo Wrist Score and the Gartland and Werley Score) and an upper extremity-specific health status questionnaire (Disabilities of the Arm, Shoulder, and Hand; DASH). Multivariate analysis of variance and multiple linear regression modeling were used to identify the degree to which various factors affect variability in the scores derived with these measures.

RESULTS

The physician-based scoring systems showed moderate correlation with each other and with DASH scores. The results of multiple linear regression modeling were as follows (percent variability accounted for by the best fit model/model with top factor alone): Mayo: 54% grip and flexion arc/47% grip alone; Gartland and Werley: 70% pain, flexion arc, radiocarpal arthritis, and duration of follow-up/53% pain alone; DASH: 71% pain, forearm arc, and type of fracture/65% pain alone.

CONCLUSIONS

At early follow-up, pain dominates the patient's perception of function after recovery from an operatively treated distal radius fracture as measured by the DASH score and the physician-based rating according to the system of Gartland and Werley. The Mayo Wrist Score is determined primarily by grip strength rather than pain. Because perception of pain and strength of grip have been shown to be influenced by psychosocial factors in some individuals, both patient-based and physician-based measures of wrist function may be vulnerable to illness behavior.

TYPE OF STUDY/LEVEL OF EVIDENCE

Prognostic III.

Perceived Control and Negative Affect Predict Expected and Experienced Acute Clinical Pain: A Structural Modeling Analysis

OBJECTIVES

Risk factors for elevated levels of clinical and experimental pain have been shown to be independently predicted by the individual's perception of personal control, negative emotional states, and pain expectancy. In this study we examine the mutual simultaneous association of these factors in the experience of dental extraction pain.

METHODS

Using structural equation modeling we examined the relationship between desired and predicted personal control, negative emotional state and the expectation of pain to predict worst treatment pain. A convenience sample of 381 patients receiving walk-in emergency dental treatment were enrolled. Half of the patients were randomly selected for generating the measurement model, the hold-out subsample was used to confirm the model.

RESULTS

Overall fit indices were adequate for both models [chi(2)/df > or = 1.37, Comparative Fit Index (CFI) > or = 0.96, Standardized Root-Mean-Square Residual (SRMR) < or = 0.05, Root Mean Square Error of Approximation (RMSEA) < or = 0.06], coefficients of determination were meaningful (R(2) > or = 0.14), and factor loadings (beta's) were significant (P's < 0.001) for each step in both models.

DISCUSSION

A sequential pathway was revealed wherein patients' desire for control over the aversiveness of treatment and their prediction of having control over those events (whether desired or not) facilitated a negative emotional state. Negative emotional state in turn influenced expected treatment pain and subsequently the level of treatment pain actually experienced. We conclude that the perception of personal control is a clinically important and cognitively-mediated factor that influences the level of acute pain experienced during stressful clinical procedures.

Anterolateral prefrontal cortex mediates the analgesic effect of expected and perceived control over pain

Perceived control attenuates pain and pain-directed anxiety, possibly because it changes the emotional appraisal of pain. We examined whether brain areas associated with voluntary reappraisal of emotional experiences also mediate the analgesic effect of perceived control over pain. Using functional magnetic resonance imaging, we compared self-controlled noxious stimuli with physically identical stimuli that were externally controlled. Self-controlled stimulation was accompanied by less pain and anxiety and higher activation in dorsal anterior cingulate (dACC), right dorsolateral, and bilateral anterolateral prefrontal (alPFC) cortices. Activation in dACC and right alPFC was negatively correlated with pain intensity ratings. For externally controlled pain, activation in right alPFC was inversely correlated with the participants' general belief to have control over their lives. Our results are consistent with a reappraisal view of control and suggest that the analgesic effect of perceived control relies on activation of right alPFC. Failure to activate right alPFC may explain the maladaptive effects of strong general control beliefs during uncontrollable pain.

The Role of Mood States Underlying Sex Differences in the Perception and Tolerance of Pain

While sex differences in pain reporting are frequently observed, the reasons underlying these differences remain unclear. The present study examined sex differences in self-report and physiological measures of pain threshold and tolerance following the administration of two laboratory pain-induction tasks. The primary study aim centered on determining whether repeated exposure to such tasks would yield sex differences in terms of pain threshold and tolerance. In addition, it was hypothesized that if such differences did exist, negative mood states might account for changes in pain ratings, threshold, and/or tolerance in subsequent exposure to noxious stimuli. Recruited from a convenience sample, 66 participants (44 female and 22 male) were exposed to both thermal and cold noxious stimuli at three separate times, while psychophysiological and self-report data were collected. Because women outnumbered men 2:1, Fisher z transformations were performed to determine whether the observed associations between mood states and pain ratings differed. We found stronger associations between fatigue and thermal-heat pain ratings for men at their first and third exposure to the pain task compared to women (z = 2.11, P < 0.05; z = 3.14, P < 0.001, respectively). Results indicated that women evidenced greater pain tolerance than men on both a behavioral and physiological level; however, they reported greater pain severity than men. Fatigue was also found to be particularly important to reports of pain severity in men and pain tolerance in response to noxious stimuli for women. Possible pathways in which mood states influenced these endpoints are discussed.

Use of the anxiety control questionnaire in psychiatric inpatients

We studied the reliability and validity of a measure of perceived control-the Anxiety Control Questionnaire (ACQ)-in a group of psychiatric inpatients. Eighty-nine patients hospitalized on a short-term, university-based psychiatric inpatient unit completed the ACQ, Anxiety Sensitivity Index, Beck Depression Inventory-II, Spielberger State-Trait Anxiety Inventory, MacArthur Admission Experience Survey, and the Lehman Quality of Life Interview. The reliability and validity of the ACQ were consistent with expectations based on prior research with outpatients. Lower levels of perceived control were associated with higher levels of depression and anxiety, lower subjective quality of life, and more perceptions of negative pressure associated with hospital admission. The findings support the potential of the ACQ as a measure of perceived control in psychiatric inpatients. Treatment implications are discussed.

The role of experiential avoidance in acute pain tolerance: a laboratory test

The present investigation examined the role of experiential avoidance in terms of acute pain tolerance and subsequent recovery. Seventy nonclinical participants completed the Acceptance and Action Questionnaire and underwent a well-established cold pressor task. Results indicated that individuals reporting higher levels of experiential avoidance had lower pain endurance and tolerance and recovered more slowly from this particular type of aversive event. Consistent with theoretical prediction, these findings suggest that experiential avoidance may play a role in tolerance of acute pain.

Ethnic differences in thermal pain responses: a comparison of South Asian and White British healthy males

The expression and report of pain is influenced by social environment and culture. Previous studies have suggested ethnically determined differences in report of pain threshold, intensity and affect. The influence of ethnic differences between White British and South Asians has remained unexplored. Twenty age-matched, male volunteers in each group underwent evaluation. Cold and warm perception and cold and heat threshold were assessed using an ascending method of limits. Magnitude estimation of pain unpleasantness and pain intensity were investigated with thermal stimuli of 46, 47, 48 and 49 degrees C. Subjects also completed a pain anxiety questionnaire. Data was analysed using t-test, Mann-Whitney and repeated measures analysis of variance as appropriate. There were no differences in cold and warm perception between the two groups. There was a statistically significant difference between the two groups for heat pain threshold (P=0.006) and heat pain intensity demonstrated a significant effect for ethnicity (F=13.84, P=0.001). Although no group differences emerged for cold pain threshold and heat unpleasantness, South Asians demonstrated lower cold pain threshold and reported more unpleasantness at all temperatures but this was not statistically significant. Our study shows that ethnicity plays an important role in heat pain threshold and pain report, South Asian males demonstrated lower pain thresholds and higher pain report when compared with matched White British males. There were no differences in pain anxiety between the two groups and no correlations were identified between pain and pain anxiety Haemodynamic measures and anthropometry did not explain group differences.

Temperature and the cold pressor test

As a method of experimental pain induction, the cold pressor test is thought to mimic the effects of chronic conditions effectively. A survey of previous studies using the cold pressor, however, revealed a lack of standardization and control of water temperature, questioning comparability and reliability. This study reports the influence of temperature on pain tolerance and intensity by using a commercially available circulating water bath. Twenty-six participants (12 men, 14 women) underwent 4 cold pressor trials with temperature order counterbalanced across 1 degrees C, 3 degrees C, 5 degrees C, and 7 degrees C, temperatures representative of the range used in previous literature. After each cold immersion participants rated pain intensity on a visual analogue scale and the McGill Pain Questionnaire. Tolerance times were recorded for each trial. Significant main effects of temperature were found for tolerance time, with higher temperatures resulting in longer times, and pain intensity, with lower temperatures resulting in higher intensities. Gender differences were found, with men tolerating the stimulus for significantly longer than women. It was concluded that small differences in water temperature have a significant effect on pain intensity and tolerance time. The use of cold pressor equipment that ensures a precise constant temperature of circulating water is necessary to ensure comparable and reliable results.

PERSPECTIVE

The cold pressor method of experimental pain induction has been widely used in the evaluation of psychological and physiological pain treatments. This article highlights the need for clear methodologic guidelines for the technique and demonstrates that very minor changes in experimental protocol can produce significant differences.

The effects of failing to control pain: an experimental investigation

Chronic pain patients are often confronted with repeated failure to achieve pain relief. The aim of this study was to experimentally investigate the effects of repeated failing attempts to control pain on pain impact (pain intensity, emotional and physiological responses). Perceived control over an electrocutaneous pain stimulus was manipulated between subjects by success or failure feedback on a task by which control over pain could be acquired. In addition, success or failure at the task was manipulated without suggesting a possibility to control pain. It was hypothesized that successful control would lead to lowest pain impact, whereas failure to control pain would lead to even higher pain impact than absent control. Furthermore, it was hypothesized that failure feedback would increase pain impact when compared to success feedback. Results indicated that repeated failure to control pain increased anger and heart rate responses compared to the other conditions, but not pain intensity. It is concluded that persistent efforts to control pain in the face of failure may lead to the maintenance or exacerbation of physiological and emotional responses.