Investigating the effects of anxiety sensitivity and coping on the perception of cold pressor pain in healthy women

Pain sensitivity after Roux-en-Y gastric bypass - associations with chronic abdominal pain and psychosocial aspects

OBJECTIVES

The aims of this study were to investigate modifications in pain sensitivity after RYGB and to explore associations between pain sensitivity and weight loss, chronic abdominal pain, total body pain, anxiety, depression, and pain catastrophizing.

METHODS

In total, 163 patients with obesity were examined with a cold pressor test for pain sensitivity before and two years after RYGB. Two aspects of pain sensitivity were registered: Pain intensity (numeric rating scale, range 0-10) and pain tolerance (seconds). Associations between pain sensitivity and the explanatory variables were assessed with linear regression.

RESULTS

Two years after RYGB the pain intensity increased (mean ± SD 0.64 ± 1.9 score units, p<0.001). Pain tolerance decreased (7.2 ± 32.4 s, p=0.005). A larger reduction in body mass index was associated with increased pain intensity, β=-0.090 (95 % CI -0.15 to -0.031, p=0.003), and decreased pain tolerance β=1.1 (95 % CI 0.95 to 2.2, p=0.03). Before surgery, participants with chronic abdominal pain reported 1.2 ± 0.5 higher pain intensity (p=0.02) and had 19.2 ± 9.3 s lower pain tolerance (p=0.04) than those without abdominal pain. No differences in pain sensitivity were observed between participants who did or did not develop chronic abdominal pain after RYGB. Pain sensitivity was associated with symptoms of anxiety but not with pain catastrophizing, depression or bodily pain.

CONCLUSIONS

The pain sensitivity increased after RYGB and was associated with larger weight loss and anxiety symptoms. Changes in pain sensitivity were not associated with development of chronic abdominal pain after RYGB in our study.

Neuropathic Pain and Spinal Cord Injury: Management, Phenotypes, and Biomarkers

Chronic neuropathic pain after a spinal cord injury (SCI) continues to be a complex condition that is difficult to manage due to multiple underlying pathophysiological mechanisms and the association with psychosocial factors. Determining the individual contribution of each of these factors is currently not a realistic goal; however, focusing on the primary mechanisms may be more feasible. One approach used to uncover underlying mechanisms includes phenotyping using pain symptoms and somatosensory function. However, this approach does not consider cognitive and psychosocial mechanisms that may also significantly contribute to the pain experience and impact treatment outcomes. Indeed, clinical experience supports that a combination of self-management, non-pharmacological, and pharmacological approaches is needed to optimally manage pain in this population. This article will provide a broad updated summary integrating the clinical aspects of SCI-related neuropathic pain, potential pain mechanisms, evidence-based treatment recommendations, neuropathic pain phenotypes and brain biomarkers, psychosocial factors, and progress regarding how defining neuropathic pain phenotypes and other surrogate measures in the neuropathic pain field may lead to targeted treatments for neuropathic pain after SCI.

Anxiety sensitivity predicts depression severity in individuals with dissociative identity disorder

BACKGROUND

Anxiety sensitivity involves the fear of anxiety-related symptoms and can exacerbate both major depressive disorder and posttraumatic stress disorder (PTSD) symptoms. However, it is unclear if anxiety sensitivity plays a similar role in dissociative identity disorder (DID) where symptoms of depression and PTSD commonly co-occur. We examined the association between anxiety sensitivity, depression, PTSD and dissociative symptoms in DID, hypothesizing a positive association between all symptoms and anxiety sensitivity.

METHOD

Participants were 21 treatment-seeking adult females with histories of childhood trauma, current PTSD, and DID. Participants completed the Anxiety Sensitivity Index (ASI), Beck Depression Inventory-II, Childhood Trauma Questionnaire, Multidimensional Inventory of Dissociation, and PTSD Checklist for DSM-5. The ASI included subscales that assessed anxiety sensitivity in cognitive, physical, and social domains.

RESULTS

Participants reported high levels of anxiety sensitivity. A multiple regression analysis demonstrated that the ASI cognitive subscale was the strongest predictor of depressive symptoms. No direct associations were identified between anxiety sensitivity and PTSD or dissociative symptoms. We conducted a mediation analysis to test an indirect relationship between cognitive anxiety sensitivity and dissociative symptoms, and found a significant indirect effect through depressive symptoms.

CONCLUSIONS

Our results suggest that cognitive anxiety sensitivity or the fear of cognitive dyscontrol is linked with symptom severity in DID. These findings emphasize the need to assess for and utilize interventions that target anxiety sensitivity, which may in turn alleviate symptoms of depression and dissociation in DID.

Anxiety sensitivity and Pain Experience: a prospective investigation among World Trade Center Responders

Chronic pain is a significant public health problem and is exacerbated by stress. The World Trade Center (WTC) Disaster represents a unique stressor, and responders to the WTC disaster are at increased risk for pain and other health complaints. Therefore, there is a significant need to identify vulnerability factors for exacerbated pain experience among this high-risk population. Anxiety sensitivity (AS), defined as fear of anxiety-related sensations, is one such vulnerability factor associated with pain intensity and disability. Yet, no work has tested the predictive effects of AS on pain, limiting conclusions regarding the predictive utility and direction of associations. Therefore, the current study examined the prospective associations of AS, pain intensity, and pain interference among 452 (M_age = 55.22, SD = 8.73, 89.4% male) responders to the WTC disaster completing a 2-week daily diary study. Using multi-level modeling, AS total score was positively associated with both pain intensity and pain interference, and that AS cognitive concerns, but not social or physical concerns, were associated with increased pain. These results highlight the importance of AS as a predictor of pain complaints among WTC responders and provide initial empirical evidence to support AS as a clinical target for treating pain complaints among WTC responders.

Perceived Racial Discrimination and Pain Intensity/Disability Among Economically Disadvantaged Latinos in a Federally Qualified Health Center: The Role of Anxiety Sensitivity

The present study examined the role of anxiety sensitivity (AS; fear of the negative consequences of anxiety) in the relation between perceived racial discrimination and pain-related problems among Latinos seeking health services at a Federally Qualified Health Center. Participants included 145 adult Latinos (87.80% female, M_age = 38.07 years, SD = 11.98, and 96.2% reported Spanish as their first language). Results indicated that perceived racial discrimination was indirectly related to the pain intensity and pain disability through AS. These effects were evident above and beyond the variance accounted for by gender, age, marital status, educational status, employment status, years living in the United States, and number of axis I diagnoses. Overall, the present findings highlight the merit in focusing further scientific attention on the interplay between perceived racial discrimination and AS to better understand and inform interventions to reduce pain problems among Latinos in primary care.

Neuropathic Pain and Spinal Cord Injury: Phenotypes and Pharmacological Management

Chronic neuropathic pain is a complicated condition after a spinal cord injury (SCI) that often has a lifelong and significant negative impact on life after the injury; therefore, improved pain management is considered a significant and unmet need. Neuropathic pain mechanisms are heterogeneous and the difficulty in determining their individual contribution to specific pain types may contribute to poor treatment outcomes in this population. Thus, identifying human neuropathic pain phenotypes based on pain symptoms, somatosensory changes, or cognitive and psychosocial factors that reflect specific spinal cord or brain mechanisms of neuropathic pain is an important goal. Once a pain phenotype can be reliably replicated, its relationship with biomarkers and clinical treatment outcomes can be analyzed, and thereby facilitate translational research and further the mechanistic understanding of individual differences in the pain experience and in clinical trial outcomes. The present article will discuss clinical aspects of SCI-related neuropathic pain, neuropathic pain phenotypes, pain mechanisms, potential biomarkers and pharmacological interventions, and progress regarding how defining neuropathic pain phenotypes may lead to more targeted treatments for these difficult pain conditions.

The effect of anxiety sensitivity on psychological and biological variables during the cold pressor test

We examined the relationship between anxiety sensitivity (AS) and autonomic nervous system responses (ANS) during the cold pressor test (CPT). Seventy-four university students participated and were divided into low-AS (M=9.06, SD=3.97) and high-AS groups (M=28.68, SD=6.63) based on AS Index scores (n's=36 and 38, respectively). The study included three phases: Rest, CPT, and Recovery. We measured the psychological variables (fear of pain and subjective pain) at pre- and post-CPT. ANS response data were collected during each phase. Fear of pain was experienced more strongly in the high-AS group (M=4.74, SD=3.25) relative to the low-AS group (M=2.72, SD=2.31), and subjective pain was also stronger in the high-AS group (M=3.08, SD=1.91) relative to the low-AS group (M=2.47, SD=1.00) in post-CPT. While parasympathetic nervous system (PNS) responses did not differ between the two groups during the CPT, the high AS-group demonstrated lower PNS activity during the Recovery phase. The high-AS group reported significantly more anticipatory fear and pain prior to the CPT, which appeared to aggravate subjective pain experiences. Furthermore, for individuals with anxiety sensitivity, ANS reactivity may be the mechanism underlying the relationship between negative affect and subjective pain.

Anxiety Sensitivity or Interoceptive Sensitivity

Abstract. The construct of anxiety sensitivity (AS) – the fear of anxiety-related symptoms – has been highly influential in current conceptualizations of anxiety disorders in general, and panic disorder specifically. However, given documented associations between AS and both non-anxiety psychological disorders as well as medical/health conditions, the extent to which measures of AS are assessing a specific fear or anxiety symptoms versus a broader fear of interoceptive or bodily sensations is unclear. Confirmatory factor analysis of data from 373 participants failed to suggest whether fears of anxiety-related symptoms were factorially distinct from fears of non-anxiety-related bodily sensations, although analyses indicated that while fears of anxiety-related symptoms were more closely associated with panic disorder severity than were fears of non-anxiety-related symptoms, both were similarly and strongly associated with hypochondriacal fears. Implications for the construct of AS, and the broader construct of somatic fears, are discussed.

Intrinsic functional connectivity of periaqueductal gray subregions in humans

The periaqueductal gray matter (PAG) is a key brain region of the descending pain modulation pathway. It is also involved in cardiovascular functions, anxiety, and fear; however, little is known about PAG subdivisions in humans. The aims of this study were to use resting-state fMRI-based functional connectivity (FC) to parcellate the human PAG and to determine FC of its subregions. To do this, we acquired resting-state fMRI scans from 79 healthy subjects and (1) used a data-driven method to parcellate the PAG, (2) used predefined seeds in PAG subregions to evaluate PAG FC to the whole brain, and (3) examined sex differences in PAG FC. We found that clustering of the left and right PAG yielded similar patterns of caudal, middle, and rostral subdivisions in the coronal plane, and dorsal and ventral subdivisions in the sagittal plane. FC analysis of predefined subregions revealed that the ventolateral(VL)-PAG was supfunctionally connected to brain regions associated with descending pain modulation (anterior cingulate cortex (ACC), upper pons/medulla), whereas the lateral (L) and dorsolateral (DL) subregions were connected with brain regions implicated in executive functions (prefrontal cortex, striatum, hippocampus). We also found sex differences in FC including areas implicated in pain, salience, and analgesia including the ACC and the insula in women, and the MCC, parahippocampal gyrus, and the temporal pole in men. The organization of the human PAG thus provides a framework to understand the circuitry underlying the broad range of responses to pain and its modulation in men and women.

Longitudinal associations between depression, anxiety, pain, and pain-related disability in chronic pain patients

OBJECTIVE

The current study sets out to examine the longitudinal relationship between pain, pain-related disability, and symptoms of depression and anxiety. The latter symptoms are highly prevalent in chronic pain and seriously impede functioning and quality of life. Nevertheless, the direction of the relationship involving these variables among individuals with chronic pain is still unclear.

METHODS

Four-hundred twenty-eight individuals with chronic pain (238 women, mean age 54.84 years, mean pain duration 85.21 months) treated at two pain clinics completed questionnaires regarding their pain (Short-Form McGill Pain Questionnaire), depression (Center for Epidemiological Studies-Depression Scale), state anxiety (State-Trait Anxiety Inventory), and pain-related disability (Pain Disability Index) at four time points, with an average of 5 months between measurements. Cross-lagged, structural equation modeling analyses were performed, enabling the examination of longitudinal associations between the variables.

RESULTS

Significant symptoms of both depression and anxiety were reported by more than half of the sample on all waves. A latent depression/anxiety variable longitudinally predicted pain (β = .27, p < .001) and pain-related disability (β = .38, p < .001). However, neither pain (β = .10, p = .126) nor pain-related disability (β = -.01, p = .790) predicted depression/anxiety.

CONCLUSIONS

Among adult patients with chronic pain treated at specialty pain clinics, high levels of depression and anxiety may worsen pain and pain-related disability.

Does anxiety sensitivity correlate with startle habituation? An examination in two independent samples

Individuals with anxiety disorders have previously demonstrated abnormal habituation to aversiveness over time. As anxiety sensitivity (AS), or an individuals' propensity to fear of anxiety-related sensations, has been shown to be a risk factor for anxiety disorders (particularly panic disorder), the present study examined whether AS was also associated with abnormal habituation. This association was examined in two independent samples of undergraduates (Ntotal=178). Habituation was operationalised as the reduction in startle response to multiple startle probes presented over 2.5 minutes and three definitions of this reduction were employed. Results indicated that individuals with higher levels of AS evidenced deficits in startle habituation, but the strength of this relationship was somewhat dependent on the definition of startle habituation, with the most robust definition being an analysis of participants' individual slopes across all nine blinks. The present findings suggest that startle habituation is a key mechanism underlying AS, and may help elucidate the role this risk factor plays in the pathogenesis of anxiety disorders.

Anxiety sensitivity as a predictor of labor pain

Psychosocial factors have been implicated in the pain experience during childbirth, which can have both short- and long-term consequences on the mother's health and her relationship with her infant. The present study evaluated important demographic, social, and psychological factors as predictors of multiple dimensions of labor pain among 35 mothers during childbirth. The results indicated that anxiety sensitivity (AS), as measured by the Anxiety Sensitivity Index, shared a significant relation with maximum pain during labor as well as sensory and affective components of pain as measured by the McGill Pain Questionnaire. AS predicted both maximum pain during labor and sensory aspects of pain above and beyond demographic and social factors as well as other theoretically important psychological factors (e.g., depression and state anxiety). These data replicate previous research that has demonstrated the significant impact of AS on pain responding in other areas (e.g., chronic pain) and extend knowledge in this literature to demonstrate the important role that AS serves among women and their experience of labor pain. Clinical implications are highlighted and discussed.

Does past pain influence current pain: biological and psychosocial models of sex differences

Previous studies have generally indicated sizeable sex differences for both laboratory pain reactivity and clinical pain reports. Numerous biological and psychosocial models have been invoked to account for these findings, but the laboratory and clinical findings have generally been examined in isolation. This paper reviews data which show a relationship between past clinical pain experiences and current responses to experimentally induced pain. Individuals with a greater pain history tend to show lower pain tolerance. Since women often have high pain experience levels and lower pain tolerance, one might ask whether the two factors are related. We review several models, based upon concepts of neonatal differences in pain reactivity, hypervigilance following early pain experiences, and concepts of peripheral and central sensitization or plasticity which might help to bridge the gap between clinical and experimental findings.

Is distraction less effective when pain is threatening? An experimental investigation with the cold pressor task

Distraction is a commonly used strategy to control pain. However there is doubt about its effectiveness as a clinical tool, and results from both experimental and clinical studies remain inconclusive. Recent theoretical advancements suggest that distraction of attention may be less effective when pain is threatening. The aim of the present study was to experimentally investigate this hypothesis. Pain-free volunteers (N=101) participated in a cold pressor test. Half of the participants simultaneously performed a cognitive distraction task, the other half did not. The threat value of the pain was manipulated by means of verbal information. The results showed that distraction resulted in less attention to the pain and lower pain ratings once the cold pressor procedure was halted. The hypothesis that the effectiveness of distraction is modulated by the threat value of pain could not be confirmed. However, threatening information increased catastrophic thoughts and anxiety, and interfered with performance on the distraction task. These findings suggest that caution is required in using distraction as a pain control strategy when the threat value is high, because fearful appraisal of pain is associated with less engagement in distraction tasks.

Measures of anxiety: is there a difference in their ability to predict functioning at three-month follow-up among pain patients?

Independent investigators have found that pain is related to health anxiety, trait anxiety, pain-related anxiety, and anxiety sensitivity. To date, the relationship among these anxiety-related constructs has not been studied directly and little is known about their relative ability to predict adjustment to pain over time. This paper presents longitudinal data from measures given to 227 musculoskeletal pain patients. Patients were asked at the time of their first visit (T1) to a physiotherapy clinic to complete a questionnaire package including measures of these different forms of anxiety as well as pain severity, disability, negative affect, and perceived control. Approximately 3 months later (T2), 50% of patients responded to these same questionnaires. Results showed that correlations among the anxiety measures at T1 ranged from 0.35 to 0.56. Using multiple regression analyses, measures of T1 anxiety were each examined for their ability to predict unique variance in disability, negative affect, and perceptions of control measured at T1 and T2. At T1, after controlling for pain severity and other measures of anxiety, pain-related anxiety uniquely predicted both disability and negative affect, trait anxiety uniquely predicted negative affect and perceptions of control, and anxiety sensitivity uniquely predicted negative affect. At T2, after controlling for pain severity, other measures of anxiety and each respective measure of functioning at T1, health anxiety uniquely predicted disability and negative affect, although anxiety sensitivity also uniquely contributed to the prediction of negative affect. It is concluded that the importance of various forms of anxiety is dependent on the timeframe and outcome examined. Clinical implications of the findings as well as directions for future research are discussed.

Enhanced fear expression in a psychopathological mouse model of trait anxiety: pharmacological interventions

The propensity to develop an anxiety disorder is thought to be determined by genetic and environmental factors. Here we investigated the relationship between a genetic predisposition to trait anxiety and experience-based learned fear in a psychopathological mouse model. Male CD-1 mice selectively bred for either high (HAB), or normal (NAB) anxiety-related behaviour on the elevated plus maze were subjected to classical fear conditioning. During conditioning both mouse lines showed increased fear responses as assessed by freezing behaviour. However, 24 h later, HAB mice displayed more pronounced conditioned responses to both a contextual or cued stimulus when compared with NAB mice. Interestingly, 6 h and already 1 h after fear conditioning, freezing levels were high in HAB mice but not in NAB mice. These results suggest that trait anxiety determines stronger fear memory and/or a weaker ability to inhibit fear responses in the HAB line. The enhanced fear response of HAB mice was attenuated by treatment with either the α(2,3,5)-subunit selective benzodiazepine partial agonist L-838,417, corticosterone or the selective neurokinin-1 receptor antagonist L-822,429. Overall, the HAB mouse line may represent an interesting model (i) for identifying biological factors underlying misguided conditioned fear responses and (ii) for studying novel anxiolytic pharmacotherapies for patients with fear-associated disorders, including post-traumatic stress disorder and phobias.

A meta-analytic review of the association between anxiety sensitivity and pain

In recent years, anxiety sensitivity (AS) has demonstrated applicability across a wide range of conditions. An area of particular interest has been the association between AS and pain. This study aimed to provide an accounting of the magnitude of this effect across studies of both clinical and nonclinical pain. Forty-one studies (14 clinical and 27 nonclinical pain) were evaluated in this meta-analytic review and represented the study of 5,908 participants (2,093 for clinical and 3,815 for nonclinical pain studies). Results indicate that AS was strongly associated with fearful appraisals of pain, with more modest results for measures of pain tolerance/threshold and pain-related disability. Implications of these results for the treatment of chronic pain are discussed.

Lower-order pain-related constructs are more predictive of cold pressor pain ratings than higher-order personality traits

Pain is a debilitating condition affecting millions each year, yet what predisposes certain individuals to be more sensitive to pain remains relatively unknown. Several psychological factors have been associated with pain perception, but the structural relations between multiple higher- and lower-order constructs and pain are not well understood. Thus, we aimed to examine the associations between pain perception using the cold pressor task (CPT), higher-order personality traits (neuroticism, negative affectivity, trait anxiety, extraversion, positive affectivity, psychoticism), and lower-order pain-related psychological constructs (pain catastrophizing [pre- and post-], fear of pain, anxiety sensitivity, somatosensory amplification, hypochondriasis) in 66 pain-free adults. Factor analysis revealed 3 latent psychological variables: pain- or body-sensitivity, negative affect/neuroticism, and positive affect/extraversion. Similarly, pain responses factored into 3 domains: intensity, quality, and tolerance. Regression and correlation analyses demonstrated that: 1) all the lower-order pain constructs (fear, catastrophizing, and hypochondriasis) are related through a single underlying latent factor that is partially related to the higher-order negative-valence personality traits; 2) pain- or body-sensitivity was more strongly predictive of pain quality than higher-order traits; and 3) the form of pain assessment is important-only qualitative pain ratings were significantly predicted by the psychological factors.

PERSPECTIVE

Consistent with the biopsychosocial model, these results suggest multiple pain-related psychological measures likely assess a common underlying factor, which is more predictive of qualitative than intensity pain ratings. This information may be useful for the development and advancement of pain assessments and treatments while considering the multidimensional nature of pain.

Acceptance, mindfulness, and values-based action may counteract fear and avoidance of emotions in chronic pain: an analysis of anxiety sensitivity

People often respond with distress and avoidance to their own negative experiences, such as the physical, cognitive, and emotional aspects of depression or anxiety. When people with chronic pain respond this way, their overall level of distress may increase, they may struggle to avoid their emotional experiences, and their daily functioning may decrease. The purpose of this study was to examine the role of anxiety sensitivity (AS), or "fear of anxiety," in relation to these processes. It was predicted that those persons with chronic pain who report higher AS will also report higher emotional distress and greater disability caused by chronic pain. A second purpose was to examine whether therapeutic processes designed to reduce emotional avoidance, namely, acceptance, mindfulness, and values, could be demonstrated to reduce the role of AS in relation to this distress and disability based on a statistical model including these variables. Subjects were 125 consecutive adult patients (64.8% women) seeking services from a specialty pain service in the United Kingdom. All patients completed a standard set of measures of AS, acceptance of pain, mindfulness, and values-based action, as well as measures of pain, disability, and emotional functioning, at their initial consultation, and these data formed the basis for the current study. In correlation and regression analyses, AS was associated with greater pain, disability, and distress. In regression analyses, the 3 proposed therapeutic processes reduced the average variance accounted for by AS in patient functioning from DeltaR(2) = .21 to DeltaR(2) = .048. This means that when the 3 therapeutic variables are taken into account statistically, AS alone retained relatively little association with patient functioning. These results suggest that AS may amplify the impact of emotional distress on patient functioning in chronic pain and that processes of acceptance, mindfulness, and values-based action may reduce this effect.

PERSPECTIVE

Humans can fear and struggle to avoid their own emotional experiences, even when these cannot harm them. Data presented here show individuals with chronic pain have more distress and disability when they manifest more fear of anxiety symptoms, and behavior patterns of "acceptance" and "mindfulness" may reduce this effect.

Anxiety sensitivity, body vigilance and fear of pain

The aim of the present study was to investigate the role of anxiety sensitivity (AS) as a factor relevant to pain and pain persistence. Two studies were conducted to examine the relationship between AS, body vigilance and the experience of pain in non-clinical samples. Study 1 investigated the relationship between AS and body vigilance that was operationalized by the detection latency for innocuous electrical stimuli; trait anxiety and neuroticism were also included as covariates. Results indicated that the high AS group (N=69) presented shorter detection latency than the low AS group (N=70); neuroticism and trait anxiety did not have significant effects on detection latency. Using another sample, Study 2 investigated the relationship between AS, body vigilance, pain tolerance, catastrophizing, and self-reported distress and pain during a cold pressor task. Neuroticism, trait anxiety and fear of pain were included as covariates. Results showed significant differences between high- (N=66) and low- (N=69) AS groups in body vigilance, catastrophizing and tolerance. The covariates neuroticism, trait anxiety and fear of pain did not have any significant effects. No significant differences were found in pain and distress ratings. Results from both studies support the importance of AS in body vigilance and the experience of pain. The theoretical, preventive and clinical implications of these findings are discussed.

Understanding the Role of Injury/Illness Sensitivity and Anxiety Sensitivity in (Automatic) Pain Processing: An Examination Using the Extrinsic Affective Simon Task

Three fundamental fears are assumed to underlie psychopathology: Anxiety Sensitivity (AS), Injury/illness sensitivity (IS), and Fear of Negative Evaluation (FNE). Both AS and IS may form risk factors for the development and exacerbation of chronic pain. The current research examines the relation between these fears and automatic threat appraisal for pain-related stimuli. Study 1 (n=48) additionally examined content-specific associations of AS and FNE with the automatic threat appraisal of, respectively, panic and social evaluative cues. Study 2 (n=60) additionally focused on the association of IS and AS with the engagement in health protecting behavior, and the use of health care services. Both studies found evidence for an automatic threat appraisal of aversive stimuli. Study 2 demonstrated a positive association between the automatic threat appraisal for pain-related stimuli and individuals' IS levels. IS was found to be the single best predictor of the tendency to engage in health protecting behavior, whereas AS was the single best predictor of the reported use of health care services.

PERSPECTIVE

This study contributes to the field of knowledge on putative risk factors for chronic pain. Results demonstrate an automatic threat appraisal toward pain-related stimuli that is related to vulnerability traits for pain. This automatic threat appraisal might initiate relatively spontaneous (nonstrategic) pain-maintaining behavioral responses.

Opioid modulation of reflex versus operant responses following stress in the rat

In pre-clinical models intended to evaluate nociceptive processing, acute stress suppresses reflex responses to thermal stimulation, an effect previously described as stress-induced "analgesia." Suggestions that endogenous opioids mediate this effect are based on demonstrations that stress-induced hyporeflexia is enhanced by high dose morphine (>5 mg/kg) and is reversed by naloxone. However, reflexes and pain sensations can be modulated differentially. Therefore, in the present study direct comparisons were made of opioid agonist and antagonist actions, independently and in combination with acute restraint stress in Long Evans rats, on reflex lick-guard (L/G) and operant escape responses to nociceptive thermal stimulation (44.5 degrees C). A high dose of morphine (>8 mg/kg) was required to reduce reflex responding, but a moderate dose of morphine (1 mg/kg) significantly reduced escape responding. The same moderate dose (and also 5 mg/kg) of morphine significantly enhanced reflex responding. Naloxone (3 mg/kg) significantly enhanced escape responding but did not affect L/G responding. Restraint stress significantly suppressed L/G reflexes (hyporeflexia) but enhanced escape responses (hyperalgesia). Stress-induced hyperalgesia was significantly reduced by morphine and enhanced by naloxone. In contrast, stress-induced hyporeflexia was blocked by both naloxone and 1 mg/kg of morphine. Thus, stress-induced hyperalgesia was opposed by endogenous opioid release and by administration of morphine. Stress-induced hyporeflexia was dependent upon endogenous opioid release but was counteracted by a moderate dose of morphine. These data demonstrate a differential modulation of reflex and operant outcome measures by stress and by separate or combined opioid antagonism or administration of morphine.

Anxiety sensitivity and pain: generalisability across noxious stimuli

Anxiety sensitivity, a fear of anxiety-related symptoms, has been associated with a heightened experience of pain, especially within women. The majority of experimental studies investigating this association have relied heavily on the cold pressor technique as a means of pain induction, limiting the generalisability of results. The aim of the current study was to extend previous research by using two types of pain stimuli (cold and heat) to determine whether the link between anxiety sensitivity and pain generalises beyond cold pressor pain. The pain experience of 125 participants in response to these stimuli was assessed using threshold and tolerance readings, as well as subjective pain ratings. Results indicated a positive association between anxiety sensitivity and subjective pain, with this association observed primarily in females. Although analysis also indicated a basic generalisability of results across pain stimuli, anxiety sensitivity effects appeared to be especially pronounced during heat stimulation. These findings suggest that those high in anxiety sensitivity may respond more negatively to specific types of pain. Possible implications along with suggestions for future research are discussed.

The role of anxiety sensitivity in subjective and physiological responses to social and physical stressors

This study examined the specificity of the relationship between anxiety sensitivity (AS), a measure of catastrophizing about arousal-related sensations, and pain responses, by examining the effect of AS on responses to stressors of a physical and social nature. Healthy men and women (n = 129) between the ages of 18 and 25 years were recruited from the community to participate in a study examining subjective, cognitive and behavioural responses to different types of stressors. Participants were randomly assigned to one of 3 groups: (i) a neutral condition in which they sat quietly and read a popular magazine; (ii) a social stress condition in which they anticipated having to give a self-disclosing speech; and (iii) a physical stress condition in which they were presented with 3 countdown to shock trials where a mild electrical shock was administered on the non-dominant arm. Subjective ratings and physiological responses were recorded in anticipation of the stressor and immediately after stress exposure. Results indicated that AS was indirectly related to pain ratings via its effect on anticipatory anxiety ratings. AS was associated with anticipatory anxiety ratings, regardless of whether the stressor was of a physical or social nature. Furthermore, AS was not shown to be directly associated with exaggerated subjective or physiological reactions to the physical stressor. These results indicate that the role of AS in pain responses may be mediated through a global effect on anxiety, and limited to the anticipatory stage of the pain experience. If future studies yield similar findings in pain patients, then they would suggest that interventions for helping individuals high in AS should focus on catastrophic thinking in anticipation of stressors in general, rather than on pain-specific stressors.

A brief cognitive-behavioral approach to reducing anxiety sensitivity decreases pain-related anxiety

Anxiety sensitivity (AS; fear of anxiety-related sensations) is a known risk factor for anxiety disorders and recently has been linked to pain disorders. The present study was guided by the hypothesis that a program designed to reduce AS levels might also result in a decrease in anxiety related to pain sensations. Female undergraduates, selected as either high or low in AS according to screening scores on the Anxiety Sensitivity Index (ASI), were randomly assigned to participate in 3 1-hour, small group sessions of either cognitive behavioral therapy (CBT; psycho-education, cognitive restructuring, and interoceptive exposure) or a non-specific treatment (NST). Immediately prior to and following the intervention, participants completed the 20-item Pain Anxiety Symptoms Scale (PASS-20). Consistent with hypothesis, results revealed a 3-way interaction between AS group, intervention condition, and time on PASS-20 total scores. Only participants with high pre-morbid levels of AS assigned to the CBT condition showed a significant reduction in scores on the PASS-20 from pre- to post-treatment. Implications for improving CBT approaches for pain disorders are discussed.

Relationships among anxious symptomatology, anxiety sensitivity and laboratory pain responsivity in children

Existing laboratory-based research in adult samples has suggested that anxiety sensitivity (AS) increases an individual's propensity to experience pain-related anxiety, which in turn enhances pain responsivity. Such relationships have not been examined in younger populations. Thus, the present study used structural equation modeling (SEM) to test a conceptual model in which AS would evidence an indirect relationship with pain intensity via its contribution to state-specific anticipatory anxiety in relation to a variety of laboratory pain tasks (cold pressor, thermal heat, and pressure pain) in 234 healthy children (116 girls; mean age = 12.6 years, range = 8-18 years). The model further hypothesized that existing anxious symptomatology would demonstrate a direct relationship with pain intensity. Results of the SEM supported the proposed conceptual model with the total indirect effect of AS accounting for 29% of the variance in laboratory pain intensity via its effects on pain-related anticipatory anxiety. AS did not however, evidence a direct relationship with pain intensity. Anxious symptomatology on the other hand, demonstrated a significant direct effect on pain intensity, accounting for 15% of variance. The combined effects of AS, anxiety symptoms, and anticipatory anxiety together explained 62% of the variance in pain intensity. These relationships did not differ for boys and girls, indicating no moderating effect of sex in the proposed model. The present results support the potential benefit of assessing both AS and anxiety symptoms in children prior to undergoing painful stimulation.

Differences in high and low anxiety sensitive women's responses to a laboratory-based cold pressor task

Anxiety sensitivity (AS) has been linked to a variety of disabling chronic health conditions, including pain-related conditions. A recent study has found that healthy women with high AS reported significantly higher levels of sensory and affective pain on an experimental cold pressor task compared to women with low AS. However, this study found no differences between AS groups for pain tolerance or pain threshold. In the present study, which was designed to replicate and extend these findings, 90 undergraduate university women were selected for inclusion in 1 of 2 AS groups (high or low) based on their screening scores on a 16-item measure of AS. Participants were tested individually on a lab-based cold pressor task using a variety of self-report and observer-measured variables. Data analyses revealed that, as expected, the high AS participants reported significantly more fear in response to the cold pressor on a relevant item of the McGill Pain Questionnaire-Short Form (SF-MPQ) than did the low AS participants. Also as expected, the high AS participants reported more pain in response to the cold pressor on the Present Pain Index (PPI) of the SF-MPQ than did the low AS participants. High AS participants did not differ from low AS participants on other aspects of the cold pressor response (e.g. pain threshold, pain tolerance, pain recovery). These results support the role of pain-related fear as a mediating variable between AS and increased perceived pain intensity.

Assessing the relationship between cold pressor pain responses and dimensions of the anxiety sensitivity profile in healthy men and women

Anxiety sensitivity (AS) has been shown previously to be an important factor in the perception and experience of experimentally induced pain within healthy adults. The aim of the current study was to extend this research by: (i) using the Anxiety Sensitivity Profile (ASP) as an alternative measure of AS; (ii) examining whether different coping instructions affect pain reports; and (iii) investigating potential differences between men and women. Participants were 50 healthy adults (23 males, 27 females) who were required to complete 2 versions of the cold pressor pain task; one version required the use of control instructions, whereas the other made use of acceptance-based instructions. Although the coping instructions were found to affect pain thresholds (acceptance resulted in lower thresholds), a similar pattern of correlations were found between the pain indexes and AS under both conditions. Of the ASP subscales, the gastrointestinal and cognitive concerns components were found to be the most strongly related to pain experiences. When the analysis was conducted separately for each sex, the ASP scales were related to the self-report measures of pain in women, whereas they were related to the behavioural measures of pain in men. These results not only confirm that AS is associated with experimental pain, but that there may be sex differences in this relationship.

Effects of suppression, acceptance and spontaneous coping on pain tolerance, pain intensity and distress

Wegner's Theory of Ironic Processes has been applied to study the effects of cognitive strategies to control pain. Research suggests that suppression contributes to a more distressing pain experience. Recently, the acceptance-based approach has been proposed as an alternative to cognitive control. This study assessed the tolerance time, the distress and the perceived pain intensity in three groups (suppression, acceptance and spontaneous coping groups) when the participants were exposed to a cold pressor procedure. Two hundred and nineteen undergraduates volunteered to participate. The suppression group showed the shortest tolerance time and the acceptance group showed the longest tolerance time. The acceptance group showed pain and distress immersion ratings that were significantly lower than in the other two groups, between which the differences were not significant. In the first recovery period, the suppression group showed pain and distress ratings that were higher than in the other two groups. In the second recovery period, although the acceptance group showed pain and distress ratings that were significantly lower than in the other two groups, the suppression and the spontaneous coping groups did not differ. The presence of a 'rebound' of physical discomfort and the effects of suppression on behavioural avoidance are discussed. These results support the acceptance approach in the management of pain.

The central role of gastrointestinal-specific anxiety in irritable bowel syndrome: further validation of the visceral sensitivity index

OBJECTIVES

The Visceral Sensitivity Index (VSI) was developed as the first instrument to assess gastrointestinal-specific anxiety, the cognitive, affective, and behavioral response to fear of gastrointestinal sensations, symptoms, and the context in which these visceral sensations and symptoms occur. The purpose of the current study was to a) replicate the previously reported psychometric properties of the VSI, b) assess the known-groups and concurrent validity of the instrument, and c) test conceptual hypotheses regarding gastrointestinal-specific anxiety in comparison to other general measures of psychological distress as a crucial mechanism (mediator/moderator) underlying irritable bowel syndrome diagnosis and its symptoms.

METHODS

Two undergraduate student samples (n > 500) were administered the VSI along with measures assessing presence of lower gastrointestinal symptoms, nongastrointestinal pain, health-service utilization, anxiety, depression, vitality, neuroticism, and anxiety sensitivity. Path analyses tested the hypothesis that gastrointestinal-specific anxiety mediates the relationship between affective variables and irritable bowel syndrome diagnosis and symptoms. A 'known-groups' validity approach elucidated the relevance of gastrointestinal-specific anxiety across a spectrum of irritable bowel syndrome patients.

RESULTS

Good concurrent, divergent and discriminant validity was demonstrated. Logistic regression revealed that gastrointestinal-specific anxiety is the key explanatory variable of irritable bowel syndrome diagnostic status. Path analysis demonstrated that gastrointestinal-specific anxiety mediates the relationship between general psychological distress measures and gastrointestinal symptom severity. The VSI was related to gastrointestinal, but not nongastrointestinal, symptom severity.

CONCLUSIONS

Overall, the VSI demonstrated excellent psychometric properties providing further support for its use in mechanistic studies of the role of anxiety in irritable bowel syndrome presentation.

Parent and child anxiety sensitivity: relationship to children's experimental pain responsivity

Anxiety sensitivity (AS) or fear of anxiety sensations has been linked to childhood learning history for somatic symptoms, suggesting that parental AS may impact children's responses to pain. Using structural equation modeling, we tested a conceptual model in which parent AS predicted child AS, which in turn predicted a hypothesized latent construct consisting of children's pain intensity ratings for 3 laboratory pain tasks (cold pressor, thermal heat, and pressure). This conceptual model was tested in 211 nonclinical parent-child pairs (104 girls, 107 boys; mean age 12.4 years; 178 mothers, 33 fathers). Our model was supported in girls only, indicating that the sex of the child moderated the hypothesized relationships. Thus, parent AS was related to child laboratory pain intensity via its contribution to child AS in girls but not in boys. In girls, 42% of the effect of parent AS on laboratory pain intensity was explained via child AS. In boys, there was no clear link between parent AS and child AS, although child AS was predictive of experimental pain intensity across sex. Our results are consistent with the notion that parent AS may operate via healthy girls' own fear of anxiety symptoms to influence their responses to laboratory pain stimuli.

PERSPECTIVE

The present study highlights sex differences in the links among parent and child anxiety sensitivity (fear of anxiety sensations) and children's experimental pain responses. Among girls, childhood learning history related to somatic symptoms may be a particularly salient factor in the development of anxiety sensitivity and pain responsivity.

Anxiety sensitivity as predictor of pain in patients undergoing restorative dental procedures

OBJECTIVES

The personality disposition to anxiety sensitivity refers to beliefs about negative consequences of bodily arousal. The concept has recently been successfully applied in research on chronic pain conditions. The present study investigated whether anxiety sensitivity interacts with dental fear to increase expected and experienced pain during routine dental treatment.

METHODS

Subjects were 97 patients undergoing dental procedures of excavation and filling. Anxiety dispositions were measured by the Anxiety Sensitivity Index and the Dental Anxiety Scale. Expected and experienced pain were assessed by affective and sensory verbal descriptor scales and a numerical rating scale measuring pain intensity.

RESULTS

Dentally fearful patients scoring high in anxiety sensitivity both expected and experienced more pain than low scorers did. Significant interactions were found predicting expected affective and intense pain and experienced pain intensity.

CONCLUSION

The results lend support to the assumption that dentally fearful patients with a disposition to high anxiety sensitivity amplify pain anticipations when exposed to the critical situation. When dentally fearful patients are under treatment, their beliefs about negative consequences of bodily arousal may negatively influence their evaluation of treatment related pain.

Acoustic noise in functional magnetic resonance imaging reduces pain unpleasantness ratings

Functional magnetic resonance imaging (fMRI) is increasingly used in cognitive studies. Unfortunately, the scanner produces acoustic noise during the image acquisition process. Interference from acoustic noise is known to affect auditory, visual and motor processing, raising the possibility that acoustic interference may also modulate processing of other sensory modalities such as pain. With the increasing use of fMRI in the investigation of the mechanisms of pain perception, particularly in relation to attention, this issue has become highly relevant. Pain is a complex experience, composed of sensory-discriminative, affective-motivational and cognitive-evaluative components. The aim of this experiment was to assess the effect of MRI scanner noise, compared to white noise, on the affective (unpleasantness) and the sensory-discriminative (localisation) components of pain. Painful radiant heat from a CO(2) laser was delivered to the skin of the right forearm in 24 healthy volunteers. The volunteers attended to either pain location or pain unpleasantness during three conditions: i) no noise, ii) exposure to MRI scanner noise (85 dB) or iii) exposure to white noise (85 dB). Both MRI scanner noise and white noise significantly reduced unpleasantness ratings (from 5.1 +/- 1.6 in the control condition to 4.7 +/- 1.5 (P = 0.002) and 4.6 +/- 1.6 (P < 0.001) with scanner and white noise respectively), whereas the ability to localise pain was not significantly affected (from 85.4 +/- 9.2% correct in the control condition to 83.1 +/- 10.3% (P = 0.06) and 83.9 +/- 9.5% (P = 0.27) with MRI scanner and white noise respectively). This phenomenon should be taken into account in the design of fMRI studies into human pain perception.

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.

Do fundamental fears differentially contribute to pain-related fear and pain catastrophizing? An evaluation of the sensitivity index

Three fundamental fears - anxiety sensitivity (AS), injury/illness sensitivity (IS) and fear of negative evaluation (FNE) - have been proposed to underlie common fears and psychopathological conditions. In pain research, the relation between AS and (chronic) pain processes was the subject of several studies, whereas the possible role of IS has been ignored. The current research examines the role of IS with respect to various pain-related variables in two studies. In the first study, 192 healthy college students completed the Sensitivity Index (SI; a composite measure assessing the three fundamental fears) and various pain-related questionnaires. In a second study, 60 students out of the original sample took part in a pain induction procedure and completed the SI as well. We first examined the properties of the SI. Factor analysis on the SI replicated the proposed factor structure [Taylor S. The structure of fundamental fears, J Behav Ther Exp Psychiat 1993;24:289-99]. However, some items of the ASI did show problematic loadings and were therefore excluded in subsequent analyses. The main hypothesis of the current study states that IS is a stronger predictor than AS of pain catastrophizing and fear of pain as assessed by self-report measures, and of pain tolerance and anticipatory fear of pain as assessed in a pain induction study. This hypothesis could be confirmed for all variables, except for pain tolerance, which was not predicted by any of the three fundamental fears. The current study can be considered as an impetus for devoting attention to IS in future pain research.

Differences in unpleasantness induced by experimental pressure pain between patients with fibromyalgia and healthy controls

Pain possesses both sensory and affective dimensions, which are highly correlated yet distinct. Comparison of these dimensions within experimental pain settings has resulted in the construct of relative unpleasantness. Relative unpleasantness is defined as the amount of affective unpleasantness elicited for a given sensory magnitude. The aim of this study was to determine the relationship between affective and sensory components of evoked pain in subjects with fibromyalgia (FM) and healthy controls. Here we show that patients with FM unexpectedly display less relative unpleasantness than healthy controls in response to random noxious pressure stimuli. Relative unpleasantness was not correlated with distress, anxiety, or depression, which were pronounced in the FM group. Clinical pain in patients with FM was perceived to be more unpleasant than the evoked pain stimuli. These results are consistent with the concept that chronic pain may reduce the relative unpleasantness of evoked pain sensations.