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Does sex moderate the relationship between anxiety and pain?
Psychology & Health
Abstract
Objectives:
Sex differences exist in the relationship between anxiety and pain, although findings are mixed. One reason could be because a number of anxiety measures have been used. Therefore, this study aimed to identify the core components within commonly used pain anxiety measures, and see whether these components are differentially related to sensation and pain thresholds in men and women. DESIGN, MAIN OUTCOME MEASURES: One hundred and eighty-nine healthy adults (119 female) completed the Fear of Pain Questionnaire, Pain Catastrophising Scale, Pain Anxiety Symptoms Scale, Anxiety Sensitivity Index-3 and the Depression Anxiety Stress Scale. Thermal sensation and pain thresholds, mechanical sensation and pressure pain thresholds were also collected.
Results:
A Principal Components Analysis of anxiety measures revealed three constructs: general distress, cognitive intrusion and fear of pain from injury/insult. Sex did not moderate the relationship between these anxiety constructs and sensation/pain thresholds. However, a significant main effect of sex was found to predict thermal pain thresholds.
Conclusion:
Preliminary indications suggest that pain anxiety dimensions can be reduced to three core constructs, and used to examine pain sensation. However, sex did not moderate this relationship. Further research is required to establish the extent and strength of sex differences in the relationship between anxiety and pain.
... Studies that have examined the factor structure underlying pain anxiety have identified 3 core components: general distress, fear of pain from injury/insult, and cognitive intrusion by pain. 36,38 Although our understanding of general distress and fear of pain is well developed, much less is known about cognitive intrusion. ...
... This is consistent with previous research, which showed that cognitive intrusion, fear of pain, and general distress were each unitary components of pain-related anxiety. 36,38 In study 3, we investigated the ECIP scale in a clinically diagnosed chronic pain sample and a comparison group. To further underpin the construct validity of the ECIP scale, we additionally looked at the relationship between cognitive intrusion and trait anxiety, life satisfaction, and emotion regulation. ...
... This is unsurprising given that cognitive intrusion has emerged as a single component in previous investigations of pain-related cognition. 36,38 This is not to say that cognitive intrusion stems 1986 N. Attridge et al. · 156 (2015Attridge et al. · 156 ( ) 1978Attridge et al. · 156 ( -1990 PAIN ® Table 4 Correlations between measures administered in study 3. ...
Patients with chronic pain often report their cognition to be impaired by pain, and this observation has been supported by numerous studies measuring the effects of pain on cognitive task performance. Furthermore, cognitive intrusion by pain has been identified as one of three components of pain anxiety, alongside general distress and fear of pain. While cognitive intrusion is a critical characteristic of pain, no specific measure exists designed to captures its effects. In three studies we describe the initial development and validation of a new measure of pain interruption: the Experience of Cognitive Intrusion of Pain (ECIP) scale. In Study 1, the ECIP scale was administered to a general population sample to assess its structure and construct validity. In Study 2, the factor structure of the ECIP scale was confirmed in a large general population sample experiencing no pain, acute pain, or chronic pain. In Study 3 we examined the predictive value of the ECIP scale in pain related disability in fibromyalgia patients. ECIP scale scores followed a normal distribution with good variance in a general population sample. The scale had high internal reliability and a clear one component structure. It differentiated between chronic pain and control groups, and it was a significant predictor of pain related disability over and above pain intensity and pain catastrophizing. Repairing attentional interruption from pain may become a novel target for pain management interventions, both pharmacological and non-pharmacological.
... Pain-related processes indeed appear to be a unique component of negative affect that occur in the absence of psychopathology and chronic pain. In healthy subjects, two separate principal component analyses (PCA) on a number of negative valence measures revealed separable negative affect components, including general distress, fear of pain from injury/insult, and cognitive intrusion of pain [17,18]. Delineating how these separable constructs might contribute to the anticipation of painful events across clinical populations, as well as their neural, physiological, and behavioral correlates, would be important for elucidating not only multi-level mechanisms involved in the processing of negative affect, but also their contribution to affective dysregulation. ...
... Finally, bilateral dAI mediated the relationship between PNA and anxiety, and PNA and SCRs. The PCA results suggested a two-component solution, partly replicating the previous research's three-component solutions (i.e., general distress, fear of pain from injury/insult, and cognitive intrusion of pain) [17,18]. Items loading on the GNA component related to depressed mood, anxiety, stress, lethargy, fear of negative evaluation from others, and difficulty regulating negative emotions are similar to the general distress component found previously. ...
Negative affect is considered an important factor in the etiology of depression and anxiety, and is highly related to pain. However, negative affect is not a unitary construct. To identify specific targets for treatment development, we aimed to derive latent variables of negative affect and test their unique contributions to affective processing during anticipation of unpredictable, painful shock. Eighty-three subjects (43 with depression and anxiety spectrum disorders and 40 healthy controls) completed self-report measures of negative valence and underwent neuroimaging while exploring computer-simulated contexts with and without the threat of a painful, but tolerable, shock. Principal component analysis (PCA) extracted distinct components of general negative affect (GNA) and pain-related negative affect (PNA). While elevated GNA and PNA were both indicative of depression and anxiety disorders, greater PNA was more strongly related to task-specific anxious reactivity during shock anticipation. GNA was associated with increased precuneus and middle frontal gyrus activity, whereas PNA was related to increased bilateral anterior insula activity. Anterior insula activity mediated the relationship between PNA and task-specific anxious reactivity. In conclusion, GNA and PNA have distinct neural signatures and uniquely contribute to anxious anticipation. PNA, via insula activity, may relate to arousal in ways that could contribute to affective dysregulation, and thus may be an important treatment target.
... This study is the most systematic examination of pain thresholds so far in an experimental context. By using standardised equipment and protocols, this study is easily comparable to other studies with other populations interested in pain thresholds, including general population norms (Magerl et al., 2010) or sex differences in pain (Moore et al., 2013a). This research is, however, limited by the absence of matching for IQ; although all participants were high functioning and were presumably able to understand the tasks (which did not require complex cognitive understanding), it cannot be guaranteed that this factor is unimportant. ...
... The literature on pain has begun to develop standardised procedures of QST to allow for a consistent objective examination of thresholds for pain and sensation (Rolke et al., 2006). These techniques have been successfully used to examine for sex differences in pain experience, as well as psychological predictors of pain thresholds (Moore et al., 2013a). It appears necessary at this time to examine the presentation of pain and sensation thresholds using standardised QST procedures to provide a more complete understanding of the experiences of pain in these individuals and allow us to continue forward in explaining reasons for any differences in pain expression observed. ...
In addition to the diagnostic criteria for autism spectrum disorder, a number of clinically important comorbid complaints, including sensory abnormalities, are also discussed. One difference often noted in these accounts is hyposensitivity to pain; however, evidence for this is limited. The purpose of the current review therefore was to examine sensitivity to pain of individuals with autism spectrum disorder. This review is interested in reports which consider differences in subjective experience of pain (i.e. different pain thresholds) and differences in behavioural response to pain (i.e. signs of pain-related distress). Studies were included if they were conducted with human subjects, included a clearly diagnosed autism spectrum disorder population and reported data pertaining to pain experience relative to the neurotypical population. Studies were classified as being self/parent report, clinical observations, observations of response to medical procedures or experimental examination of pain. Both self/parent report and clinical observations appeared to report hyposensitivity to pain, whereas observations of medical procedures and experimental manipulation suggested normal or hypersensitive responses to pain. This review suggests that contrary to classical reports, individuals with autism spectrum disorder do not appear to have systematically altered pain responses or thresholds. More systematic experimental examination of this area is needed to understand responses to pain of individuals with autism spectrum disorder.
... However, multiple studies have presented data that support the opposite conclusion [33,34]. Also, no evidence was found to suggest that the anxiety related to nociceptive hypersensitivity differs between males and females [35]. In this study, only male mice were applied to exclude the effect of estrogen on pain processing [36]. ...
The comorbidity of chronic pain and mental dysfunctions such as anxiety disorders has long been recognized, but the underlying mechanisms remained poorly understood. Here, using a mouse model of neuropathic pain, we demonstrated that the thalamic paraventricular nucleus (PVT) played a critical role in chronic pain-induced anxiety-like behavioral abnormalities. Fiber photometry and electrophysiology demonstrated that chronic pain increased the activities in PVT glutamatergic neurons. Chemogenetic manipulation revealed that suppression of PVT glutamatergic neurons relieved pain-like behavior and anxiety-like behaviors. Conversely, selective activation of PVT glutamatergic neurons showed algesic and anxiogenic effects. Furthermore, the elevated excitability of PVT glutamatergic neurons resulted in increased excitatory inputs to the basolateral complex (BLA) neurons. Optogenetic manipulation of the PVT-BLA pathway bilaterally modulates both the pain-like behavior and anxiety-like phenotypes. These findings shed light on how the PVT-BLA pathway contributed to the processing of pain-like behavior and maladaptive anxiety, and targeting this pathway might be a straightforward therapeutic strategy to both alleviate nociceptive hypersensitivity and rescue anxiety behaviors in chronic pain conditions.
... Only female participants were included in this study as they are twice as likely as males to be affected by depression (Hamet & Tremblay 2005) and have been reported to be more susceptible to the effects of the Acute Tryptophan Depletion (ATD) Nishizawa et al. 1997). In addition, sex differences have been reported in psychophysical ratings of touch and pain, with women reporting more clinical pain complaints and having lower experimental psychophysical thresholds (Essick et al. 1999;Moore et al. 2013;Smith et al. 2011). ...
Rationale
Affiliative tactile interactions help regulate physiological arousal and confer resilience to acute and chronic stress. C-tactile afferents (CTs) are a population of unmyelinated, low threshold mechanosensitive cutaneous nerve fibres which respond optimally to a low force stimulus, moving at between 1 and 10 cm/s. As CT firing frequencies correlate positively with subjective ratings of touch pleasantness, they are hypothesised to form the first stage of encoding affiliative tactile interactions. Serotonin is a key modulator of social responses with known effects on bonding.
Objectives
The aim of the present study was to determine the effect of acutely lowering central serotonin levels on perceptions of CT-targeted affective touch.
Methods
In a double blind, placebo-controlled design, the effect of acute tryptophan depletion (ATD) on 25 female participants’ ratings of directly and vicariously experienced touch was investigated. Psychophysical techniques were used to deliver dynamic tactile stimuli; some velocities were targeted to optimally activate CTs (1–10 cm/s), whereas other, faster and slower strokes fell outside the CT optimal range. Discriminative tactile function, cold pain threshold and tolerance were also measured.
Results
ATD significantly increased pleasantness ratings of both directly and vicariously experienced affective touch, increasing discrimination of the specific hedonic value of CT targeted velocities. While ATD had no effect on either tactile or cold pain thresholds, there was a trend for reduced tolerance to cold pain.
Conclusions
These findings are consistent with previous reports that depletion of central serotonin levels modulates neural and behavioural responsiveness to appetitive sensory signals.
... In a review paper, it was hypothesized that gender determined the differences in the perception and the experience of pain (117). In a laboratory study, men tended to exhibit a higher pain threshold compared with women (118) whereas women appear to catastrophize more, potentially increasing pain sensitivity. Coping styles are also different. ...
Research in sleep medicine over the last decades has involved a broad variety of sleep disorders in both men and women. Gender differences have been identified in sleep physiology as well as in the three most common sleep disorders: obstructive sleep apnoea (OSA), insomnia and restless legs syndrome (RLS). However, research on gender differences in sleep medicine appears limited. This clinical review aims to give an updated overview of gender differences, in relation to prevalence, clinical presentation, treatment and quality of life in OSA, insomnia and RLS. Future research directions in the adult population will also be discussed.
... According to some reviews, gender determines differences in pain perception and experience; 26 moreover, laboratory studies have shown such differences in the pain threshold, one of them being the significantly higher threshold evidenced in healthy men compared to that in women. 27 Several hypotheses have been proposed to explain the higher prevalence of chronic pain in women: (1) women are more willing to report pain, (2) women may be more exposed to biopsychosocial risk factors, which is likely to make them more vulnerable to developing chronic pain by responding differently to such risk factors, and (3) it is more likely for health effectors to diagnose women with FM. 28 Regarding psychological factors, some of them have been shown to vary in function of sex, as catastrophization of pain, coping style, and abuse history in childhood. 26 The review by Paller et al. 26 highlights that catastrophization is more common in women and that it is associated with enhanced sensitivity to experimental pain. ...
Aim:
The aim of this study was to assess the efficacy of cognitive-behavioral therapy for insomnia (CBT-I) in men and women with FM and compare sleep and clinical features between both genders.
Methods:
Fifteen women and 13 men were selected to participate in nine weekly CBT-I sessions that involved completing several self-reported questionnaires at pretreatment, post-treatment, and follow-up. Patients were recruited from the Rheumatology Service and Pain Unit of Hospital and a fibromyalgia association. Group psychotherapy was performed at clinical unit of the Faculty of Psychology.
Results:
Both groups showed significant clinical and statistical improvements in sleep quality and the main symptoms associated with FM (ie, pain intensity, fatigue, anxiety, pain catastrophizing, and pain-related anxiety). Differential treatment responsiveness between sexes was observed. Male group exhibited significant changes at post-treatment in sleep disturbances and pain-related anxiety and catastrophizing. The female group showed post-treatment improvements in sleep latency, general fatigue, and depression, which persisted at follow-up.
Conclusions:
Differential responses to treatment between men and women were observed in some sleep- and pain-related variables. Outcomes show the needed to design different treatments for men and women with FM is discussed.
... According to some reviews, gender determines differences in pain perception and experience; 26 moreover, laboratory studies have shown such differences in the pain threshold, one of them being the significantly higher threshold evidenced in healthy men compared to that in women. 27 Several hypotheses have been proposed to explain the higher prevalence of chronic pain in women: (1) women are more willing to report pain, (2) women may be more exposed to biopsychosocial risk factors, which is likely to make them more vulnerable to developing chronic pain by responding differently to such risk factors, and (3) it is more likely for health effectors to diagnose women with FM. 28 Regarding psychological factors, some of them have been shown to vary in function of sex, as catastrophization of pain, coping style, and abuse history in childhood. 26 The review by Paller et al. 26 highlights that catastrophization is more common in women and that it is associated with enhanced sensitivity to experimental pain. ...
Objectives: To date, very few studies have analyzed gender differences in patients with fibromyalgia syndrome [FMS], as the prevalence of this syndrome is much lower in males than females. The aim of this study was to explore how gender differences affect the experience of pain, physical activity and psychological measures of FMS patients compared to healthy normal controls [HNCs]. Methods: Women and men with FMS were recruited for this study. Demographically matching HNCs were recruited for comparison. A pressure algometer was used to measure patients' pressure pain thresholds [PPTs]. Participants completed the visual analog scale of the McGill Pain Questionnaire, the Modified Baecke Physical Activity Questionnaire, the Pittsburgh Sleep Quality Index and the Fibromyalgia Impact Questionnaire. Results: Thirty-eight patients with FMS [21 women and 17 men] and 32 HNCs [18 women and 14 men] participated in the study. The PPTs, physical activity and psychological measures showed no significant gender differences between male and female FMS patients [p > 0.05]. Post-hoc analyses showed significant differences in sleep quality and pain intensity between FMS patients and HNCs [p < 0.05]. Regarding physical activity, significant differences were found between men with FMS and healthy men in household activities [p < 0.05]. In women with FMS, sleep quality was negatively correlated with two measures of physical activity [sport and leisure time, p < 0.05]. In men, no significant correlations were found between the measures assessed. Conclusion: These findings suggest that the abnormal nociceptive processing recognized in FMS is similar between genders. As expected, FMS patients rated pain sensations higher on all scales compared to healthy groups. In addition, male and female FMS patients had lower pain thresholds than HNCs. In women with FMS, only sleep quality was significantly correlated with physical activity. Further studies with larger samples are needed to confirm these results.
... Psychological and social factors are regarded as important for predicting long term pain-related disability (Watson and Kendall, 2000;Hill and Fritz, 2011;Linton and Shaw, 2011;Nicholas et al., 2011). Their role in determining or modulating the individual's pain experience, as postulated in Neuromatrix Theory, is now well established (Carter et al., 2002;Campbell and Edwards, 2009;Main and George, 2011;van Ryckeghem et al., 2012;Moore et al., 2013;Ruscheweyh et al., 2013;Taylor et al., 2013). Psychosocial factors are important in the clinical presentations of people with ongoing pain states but also of people with a recent onset of pain. ...
Pain is no longer considered to be simply the transmission of nociception, but rather an output subsequent to the complex interactions of homeostatic systems. Manual therapists’ clinical reasoning needs to incorporate this complexity in order to develop individualised effective treatment plans.
Pain classification strategies attempting to assist clinical reasoning traditionally define multiple types of pain - nociceptive, neuropathic, centrally sensitised – potentially fitting elements of the pain experience to linear independent systems, rather than embracing the multiple dimensions. It is our contention that pain should not be classified unidimensionally. In all pain states consideration should be given to the combined influence of physiological, cognitive, emotional and social inputs, all of which have the potential to influence nociception.
The Pain and Movement Reasoning Model presented in this paper attempts to capture the complexity of the human pain experience by integrating these multiple dimensions into a decision making process. Three categories have been created to facilitate this - central modulation, regional influences, and local stimulation. The Model allows for the identification of a predominant element to become the focus of treatment but also for the identification of changes to clinical presentation, where new treatment targets can emerge.
All studies that investigated personal factors influencing pressure pain threshold (PPT) in healthy people were synthesized. Data was summarized, and risk of bias (RoB) and level of evidence were determined. Results were pooled per influencing factor, grouped by body region and included in meta-analyses. Fifty-four studies were eligible. Five had low, nine moderate, and 40 high RoB. Following meta-analyses, a strong conclusion was found for the influence of scapular position, a moderate for the influence of gender, and a weak for the influence of age (shoulder/arm region) and blood pressure on PPT. In addition, body mass index, gender (leg region), alcohol consumption and pain vigilance may not influence PPT. Based on qualitative summary, depression and menopause may not influence PPT. For other variables there was only preliminary or conflicting evidence. However, caution is advised, since the majority of included studies showed a high RoB and several were not eligible to include in meta-analyses. Heterogeneity was high in the performed meta-analyses, and most conclusions were weak. More standardized research is necessary.
Numerous emotion-based constructs seem related to pain and pain-related disability. These include general affect constructs such as anxiety and depression, as well as specific anxiety-related constructs such as anxiety sensitivity and fear of pain. Few studies examine the relationships between these constructs. Those that have suggest they can be reduced to three or four underlying components. We used a confirmatory approach to test the models of pain-related anxiety found in previous exploratory studies. Adult participants (N = 294) completed commonly used measures of affect-related constructs relevant to pain. Confirmatory Factor Analyses tested three models to determine the best fit. The tripartite model, with small modifications, was found to provide the best fit. The model consisted of: 1) General distress, 2) Fear of pain from injury/insult, and 3) Cognitive intrusion of pain.
Background and aims:
Pain is known to have a disruptive effect on cognitive performance, but prior studies have used highly constrained laboratory tasks that lack ecological validity. In everyday life people are required to complete more complex sets of tasks, prioritising task completion and recalling lists of tasks which need to be completed, and these tasks continue to be attempted during episodes or states of pain. The present study therefore examined the impact of thermal induced pain on a simulated errand task.
Methods:
Fifty-five healthy adults (36 female) performed the Edinburgh Virtual Errands Task (EVET) either during a painful thermal sensation or with no concurrent pain. Participants also completed the Experience of Cognitive Intrusion of Pain (ECIP) questionnaire to measure their self-reported cognitive impact of pain in general life.
Results:
Participants who completed the EVET task in pain and who self-reported high intrusion of pain made significantly more errors than those who reported lower intrusion on the ECIP.
Conclusions:
Findings here support the growing literature that suggests that pain has a significant impact on cognitive performance. Furthermore, these findings support the developing literature suggesting that this relationship is complex when considering real world cognition, and that self-report on the ECIP relates well to performance on a task designed to reflect the complexities of everyday living.
Implications:
If extrapolated to chronic pain populations, these data suggest that pain during complex multitasking performance may have a significant impact on the number of errors made. For people highly vulnerable to cognitive intrusion by pain, this may result in errors such as selecting the wrong location or item to perform tasks, or forgetting to perform these tasks at the correct time. If these findings are shown to extend to chronic pain populations then occupational support to manage complex task performance, using for example diaries/electronic reminders, may help to improve everyday abilities.
In Study 1, the Pain Catastrophizing Scale (PCS) was administered to 425 undergraduates. Analyses yielded a three component solution comprising (a) rumination, (b) magnification, and (c) helplessness. In Study 2, 30 undergraduate participants were classified as catastrophizers (n = 15) or noncatastrophizers (n = 15) on the basis of their PCS scores and participated in an cold pressor procedure. Catastrophizers reported significantly more negative pain-related thoughts, greater emotional distress, and greater pain intensity than noncatastrophizers. Study 3 examined the relation between PCS scores, negative pain-related thoughts, and distress in 28 individuals undergoing an aversive electrodiagnostic medical procedure. Catastrophizers reported more negative pain-related thoughts, more emotional distress, and more pain than noncatastrophizers. Study 4 examined the relation between the PCS and measures of depression, trait anxiety, negative affectivity, and fear of pain. Analyses revealed moderate correlations among these measures, but only the PCS contributed significant unique variance to the prediction of pain intensity.
The factor structure, reliability, and validity of the Depression Anxiety Stress Scales (DASS; S. H. Lovibond & P. F. Lovibond, 1995) and the 21-item short form of these measures (DASS–21 ) were examined in nonclinical volunteers (
n = 49) and patients with Diagnostic and Statistical Manual of Mental Disorders (4th ed.; American Psychiatric Association, 1994) diagnoses of panic disorder (
n = 67), obsessive-compulsive disorder (
n = 54), social phobia (
n = 74), specific phobia (
n = 17), and major depressive disorder (
n = 46). This study replicates previous findings indicating that the DASS distinguishes well between features of depression, physical arousal, and psychological tension and agitation and extends these observations to the DASS–21. In addition, the internal consistency and concurrent validity of the DASS and DASS–21 were in the acceptable to excellent ranges. Mean scores for the various groups were similar to those in previous research, and in the expected direction. The implications of these findings are discussed. (PsycINFO Database Record (c) 2012 APA, all rights reserved)
In Study I, the Pain Catastrophizing Scale (PCS) was administered to 425 undergraduates. Analyses yielded a three component solution comprising (a) rumination, (b) magnification, and (c) helplessness. In Study 2, 30 undergraduate participants were classified as catastrophizers (
n = 15) or noncatastrophizers (
n = 15) on the basis of their PCS scores and participated in a cold pressor procedure. Catastrophizers reported significantly more negative pain-related thoughts, greater emotional distress, and greater pain intensity than noncatastrophizers. Study 3 examined the relation between PCS scores, negative pain-related thoughts, and distress in 28 individuals undergoing an aversive electrodiagnostic medical procedure. Catastrophizers reported more negative pain-related thoughts, more emotional distress, and more pain than noncatastrophizers. Study 4 examined the relation between the PCS and measures of depression, trait anxiety, negative affectivity, and fear of pain. Analyses revealed moderate correlations among these measures, but only the PCS contributed significant unique variance to the prediction of pain intensity. (PsycINFO Database Record (c) 2012 APA, all rights reserved)
Although patients with a depressive disorder report often of pain, their sensitivity to experimental pain is controversial, probably due to differences in sensory testing methods and to the lack of normal values. Therefore, we used a standardized and validated comprehensive sensory testing paradigm to assess the peripheral and central nervous system performance in depressive patients compared to healthy controls and chronic pain patients with fibromyalgia syndrome (FMS), in which depression is a common comorbidity. Twenty-five depressive psychiatric inpatients (pain-free: n = 20), 35 FMS outpatients and 25 healthy controls underwent quantitative sensory testing (QST), including thermal and mechanical detection and pain thresholds, pain sensitivity and responsiveness to repetitive noxious mechanical stimuli (wind-up). In depressive disorder (to a lesser extent also in FMS), significantly decreased cold pain thresholds and an increased wind-up were found, although the mechanical pain thresholds and pain sensitivity were comparable to those of the healthy controls. All the detection thresholds were within the normal range in all the groups. In depressive disorder, there were no significant side differences in the detection and pain thresholds.The results contradict the former assumption of a general insensitivity to experimental pain in depressive disorder. In the mostly pain-free patients signs of an enhanced central hyperexcitability are even more pronounced than usually found in chronic pain patients (e.g. FMS), indicating common mechanisms in depressive disorder and chronic pain in accordance with the assumption of non-pain associated mechanisms in depressive disorder for central hyperexcitability, e.g. by inhibited serotonergic function. Furthermore, this trial demonstrates the feasibility of QST in depressive patients.
This study investigated the relationship of thermal pain testing from three types of quantitative sensory testing (ie, supra-threshold stimulus response scaling, temporal summation, and after-sensation) at three anatomical sites (ie, upper extremity, lower extremity, and trunk). Pain ratings from these procedures were also compared with common psychological measures previously shown to be related to experimental pain responses and consistent with fear-avoidance models of pain. Results indicated that supra-threshold stimulus response scaling, temporal summation, and after-sensation, were significantly related to each other. The site of stimulation was also an important factor, with the trunk site showing the highest sensitivity in all three quantitative sensory testing procedures. Supra-threshold response measures were highly related to measures of fear of pain and anxiety sensitivity for all stimulation sites. For temporal summation and after-sensation, only the trunk site was significantly related to anxiety sensitivity, and fear of pain, respectively. Results suggest the importance of considering site of stimulation when designing and comparing studies. Furthermore, psychological influence on quantitative sensory testing is also of importance when designing and comparing studies. Although there was some variation by site of stimulation, fear of pain and anxiety sensitivity had consistent influences on pain ratings.
Unlabelled:
Sex-related influences on pain and analgesia have become a topic of tremendous scientific and clinical interest, especially in the last 10 to 15 years. Members of our research group published reviews of this literature more than a decade ago, and the intervening time period has witnessed robust growth in research regarding sex, gender, and pain. Therefore, it seems timely to revisit this literature. Abundant evidence from recent epidemiologic studies clearly demonstrates that women are at substantially greater risk for many clinical pain conditions, and there is some suggestion that postoperative and procedural pain may be more severe among women than men. Consistent with our previous reviews, current human findings regarding sex differences in experimental pain indicate greater pain sensitivity among females compared with males for most pain modalities, including more recently implemented clinically relevant pain models such as temporal summation of pain and intramuscular injection of algesic substances. The evidence regarding sex differences in laboratory measures of endogenous pain modulation is mixed, as are findings from studies using functional brain imaging to ascertain sex differences in pain-related cerebral activation. Also inconsistent are findings regarding sex differences in responses to pharmacologic and non-pharmacologic pain treatments. The article concludes with a discussion of potential biopsychosocial mechanisms that may underlie sex differences in pain, and considerations for future research are discussed.
Perspective:
This article reviews the recent literature regarding sex, gender, and pain. The growing body of evidence that has accumulated in the past 10 to 15 years continues to indicate substantial sex differences in clinical and experimental pain responses, and some evidence suggests that pain treatment responses may differ for women versus men.
In this article, we attempt to distinguish between the properties of moderator and mediator variables at a number of levels. First, we seek to make theorists and researchers aware of the importance of not using the terms moderator and mediator interchangeably by carefully elaborating, both conceptually and strategically, the many ways in which moderators and mediators differ. We then go beyond this largely pedagogical function and delineate the conceptual and strategic implications of making use of such distinctions with regard to a wide range of phenomena, including control and stress, attitudes, and personality traits. We also provide a specific compendium of analytic procedures appropriate for making the most effective use of the moderator and mediator distinction, both separately and in terms of a broader causal system that includes both moderators and mediators.
Research has demonstrated the importance of psychological factors in coping, quality of life, and disability in chronic pain. Furthermore, the contributions of psychology in the effectiveness of treatment of chronic pain patients have received empirical support. The authors describe a biopsychosocial model of chronic pain and provide an update on research implicating the importance of people's appraisals of their symptoms, their ability to self-manage pain and related problems, and their fears about pain and injury that motivate efforts to avoid exacerbation of symptoms and further injury or reinjury. They provide a selected review to illustrate treatment outcome research, methodological issues, practical, and clinical issues to identify promising directions. Although there remain obstacles, there are also opportunities for psychologists to contribute to improved understanding of pain and treatment of people who suffer from chronic pain. The authors conclude by noting that pain has received a tremendous amount of attention culminating in the passage of a law by the U.S. Congress designating the period 2001-2011 as the "The Decade of Pain Control and Research."
People who suffer from chronic pain are typically found to be more anxious and fearful of pain than those who do not. Recent evidence has shown that the fear itself serves as a mechanism through which chronic pain is maintained over time. Even once the muscle or tissue damage is healed, a fear of further pain can lead to avoidance behaviour, which over time, leads to deconditioning (e.g. decreased mobility, weight gain). This in turn leads to further pain experiences, negative expectancies, and strengthened avoidance. It is the reciprocal relationship between fear and avoidance that is thought to be responsible for maintaining pain behaviour and disability. With fear of pain known to cause significant suffering and functional disability, there is a need for a greater understanding of this condition. This is the first book to explore this topic. It starts by introducing the current theoretical positions regarding pain-related fear and anxiety along with relevant empirical findings. It then provides comprehensive coverage of assessment issues and treatment strategies. Finally, the book suggests further areas for investigation. Pain-related fear and anxiety are now receiving considerable attention, and efficient and effective treatments are fast becoming available. This book will help guide and extend our understanding of a condition that has been shown to be associated with substantial suffering and disability.
People who suffer from chronic pain are typically found to be more anxious and fearful of pain than those who do not. Recent evidence has shown that the fear itself serves as a mechanism through which chronic pain is maintained over time. Even once the muscle or tissue damage is healed, a fear of further pain can lead to avoidance behaviour, which over time, leads to deconditioning (e.g. decreased mobility, weight gain). This in turn leads to further pain experiences, negative expectancies, and strengthened avoidance. It is the reciprocal relationship between fear and avoidance that is thought to be responsible for maintaining pain behaviour and disability. With fear of pain known to cause significant suffering and functional disability, there is a need for a greater understanding of this condition. This is the first book to explore this topic. It starts by introducing the current theoretical positions regarding pain-related fear and anxiety along with relevant empirical findings. It then provides comprehensive coverage of assessment issues and treatment strategies. Finally, the book suggests further areas for investigation. Pain-related fear and anxiety are now receiving considerable attention, and efficient and effective treatments are fast becoming available. This book will help guide and extend our understanding of a condition that has been shown to be associated with substantial suffering and disability.
It is now generally acknowledged that sex and gender are important factors in the perception and experience of pain (Berkley, 1997; Berkley, Hoffman, Murphy, & Holdcroft, 2002; Bernardes, Keogh, & Lima, 2008; Dao & LeResche, 2000; Fillingim, 2000; Holdcroft & Berkley, 2005; Keogh, 2006; LeResche, 1999; Rollman & Lautenbacher, 2001; Wiesenfeld-Hallin, 2005). The focus of this chapter will be to review the evidence for variability in human pain experiences, as ascribed to the sex of the individual, as well as considering some of the reasons why such differences exist. As will become apparent, not only are there important biological differences that help to explain why men and women may differ, but there are a range of psychological and socio-cultural factors that need to be considered when attempting to account for sex-specific variation in pain and analgesia.
Anxiety sensitivity is defined as a trait tendency to experience a fear of anxiety-related sensations. Although closely associated with panic disorder, recent research suggests that anxiety sensitivity is related to a wider range of pathological conditions. Indeed, it has been noted that anxiety sensitivity may play a role in mediating negative experiences and sensations associated with pain. The aim of the present study was to determine the effect of anxiety sensitivity on reported negative sensations to experimentally induced pain. Measures of pain threshold and tolerance were taken, as were self-report measures of affective and sensory experiences. Because differences between males and females have been found with both anxiety sensitivity and pain experience, gender differences were also investigated. As expected, gender was found to moderate pain experiences. Females had a lower pain threshold and were less tolerant to pain than males. Gender differences were also found to be associated with sensory pain. However, this effect was dependent on levels of anxiety sensitivity. High anxiety sensitive females reported greater sensory pain than low anxiety sensitive females. No effect of anxiety sensitivity on sensory pain was found among males. These results are discussed in light of current models of anxiety sensitivity.
• There is good evidence that men and women differ with respect to the perception and experience of pain.
Women typically report more pain than men, as well as exhibit specific sex differences in the perception and emotional expression of pain. We present evidence that sex is a significant variable in the evolution of facial expression of pain.
Objective and design. In a randomized controlled study, we investigated whether pain anticipation and fear-avoidance beliefs will lead to behavioral avoidance.
Patients. Fifty patients with chronic low back pain (CLBP) performed a simple flexion_legend_span task. Before the test, members of a control group were informed that the movement would not result in any increase of pain, whereas experimental group participants were told that a slight increase of pain could occur.
Outcome measures. All patients completed the Fear-Avoidance-Beliefs Questionnaire (FABQ) and the Pain Disability Index (PDI). As dependent variables, different behavioral performance parameters were registered by a computerized protocol: number of flexion movements, mean range of motion, and mean work ratio. Furthermore, patients were asked about their pain intensity as well as their fear (at the moment) and finally were asked to judge the unpleasantness of the experiment (using visual analogue scales for each of the three variables).
Results. Inducing pain anticipation (by instruction) led to significantly lower levels of behavioral performance as well as increased pain intensity and fear during the test. Behavioral performance was significantly correlated with fear-avoidance beliefs.
Conclusions. Results confirm that pain anticipation and fear-avoidance beliefs significantly influence the behavior of patients with low back pain in that they motivate avoidance behavior. Therapists must be aware of the powerful effects of cognitive processes, which can give rise to fear of pain and, consequently, avoidance behavior.
Sex-related differences in the experience of both clinical and experimentally induced pain have been widely reported. Specifically,
females are at greater risk for developing several chronic pain disorders, and women exhibit greater sensitivity to noxious
stimuli in the laboratory compared with men. Several mechanisms have been proposed to account for these sex differences. Psychosocial
factors such as sex role beliefs, pain coping strategies, mood, and pain-related expectancies may underlie these effects.
In addition, there is evidence that familial factors can alter pain responses, and these intergenerational influences may
differ as a function of sex. Sex hormones are also known to affect pain responses, which may mediate the sex differences.
Although the magnitude of these effects has not been well characterized, there are potentially important practical implications
of sex differences in pain responses. These implications are discussed, and directions for future research are delineated.
The fear-avoidance (FA) model of chronic pain describes how individuals experiencing acute pain may become trapped into a vicious circle of chronic disability and suffering. We propose to extend the FA model by adopting a motivational perspective on chronic pain and disability.
A narrative review.
There is ample evidence to support the validity of the FA model as originally formulated. There are, however, some key challenges that call for a next generation of the FA model. First, the FA model has its roots in psychopathology, and investigators will have to find a way to account for findings that do not easily fit within such framework. Second, the FA model needs to address the dynamics and complexities of disability and functional recovery. Third, the FA model should incorporate the idea that pain-related fear and avoidance occurs in a context of multiple and often competing personal goals.
To address these 3 key challenges, we argue that the next generation of the FA model needs to more explicitly adopt a motivational perspective, one that is built around the organizing powers of goals and self-regulatory processes. Using this framework, the FA model is recast as capturing the persistent but futile attempts to solve pain-related problems to protect and restore life goals.
Fillingim and Maixner (Fillingim, R.B. and Maixner, W., Pain Forum, 4(4) (1995) 209–221) recently reviewed the body of literature examining possible sex differences in responses to experimentally induced noxious stimulation. Using a `box score' methodology, they concluded the literature supports sex differences in response to noxious stimuli, with females displaying greater sensitivity. However, Berkley (Berkley, K.J., Pain Forum, 4(4) (1995) 225–227) suggested the failure of a number of studies to reach statistical significance suggests the effect may be small and of little practical significance. This study used meta-analytic methodology to provide quantitative evidence to address the question of the magnitude of these sex differences in response to experimentally induced pain. We found the effect size to range from large to moderate, depending on whether threshold or tolerance were measured and which method of stimulus administration was used. The values for pressure pain and electrical stimulation, for both threshold and tolerance measures, were the largest. For studies employing a threshold measure, the effect for thermal pain was smaller and more variable. The failures to reject the null hypothesis in a number of these studies appear to have been a function of lack of power from an insufficient number of subjects. Given the estimated effect size of 0.55 threshold or 0.57 for tolerance, 41 subjects per group are necessary to provide adequate power (0.70) to test for this difference. Of the 34 studies reviewed by Fillingim and Maixner, only seven were conducted with groups of this magnitude. The results of this study compels to caution authors to obtain adequate sample sizes and hope that this meta-analytic review can aid in the determination of sample size for future studies.
This systematic review summarizes the results of 10 years of laboratory research on pain and sex/gender. An electronic search strategy was designed by a medical librarian to access multiple databases. A total of 172 articles published between 1998 and 2008 were retrieved, analyzed, and synthesized. The second set of results presented in this review (129 articles) examined various biopsychosocial factors that may contribute to differences in pain sensitivity between healthy women and men. The results revealed that the involvement of hormonal and physiological factors is either inconsistent or absent. Some studies suggest that temporal summation, allodynia, and secondary hyperalgesia may be more pronounced in women than in men. The evidence to support less efficient endogenous pain inhibitory systems in women is mixed and does not necessarily apply to all pain modalities. With regard to psychological factors, depression may not mediate sex differences in pain perception, while the role of anxiety is ambiguous. Cognitive and social factors appear to partly explain some sex-related differences. Finally, past individual history may be influential in female pain responses. However, these conclusions must be treated with much circumspection for various methodological reasons. Furthermore, some factors/mechanisms remain understudied in the field. There is also a need to assess and improve the ecological validity of findings from laboratory studies on healthy subjects, and perhaps a change of paradigm needs to be considered at this point in time to better understand the factors that influence the experience of women and men who suffer from acute or chronic pain.
The purpose of this systematic review was to summarize and critically appraise the results of 10 years of human laboratory research on pain and sex/gender. An electronic search strategy was designed by a medical librarian and conducted in multiple databases. A total of 172 articles published between 1998 and 2008 were retrieved, analyzed, and synthesized. The first set of results (122 articles), which is presented in this paper, examined sex difference in the perception of laboratory-induced thermal, pressure, ischemic, muscle, electrical, chemical, and visceral pain in healthy subjects. This review suggests that females (F) and males (M) have comparable thresholds for cold and ischemic pain, while pressure pain thresholds are lower in F than M. There is strong evidence that F tolerate less thermal (heat, cold) and pressure pain than M but it is not the case for tolerance to ischemic pain, which is comparable in both sexes. The majority of the studies that measured pain intensity and unpleasantness showed no sex difference in many pain modalities. In summary, 10 years of laboratory research have not been successful in producing a clear and consistent pattern of sex differences in human pain sensitivity, even with the use of deep, tonic, long-lasting stimuli, which are known to better mimic clinical pain. Whether laboratory studies in healthy subjects are the best paradigm to investigate sex differences in pain perception is open to question and should be discussed with a view to enhancing the clinical relevance of these experiments and developing new research avenues.
Pain is known to disrupt attentional performance in both healthy adults and patients with chronic pain. Exactly which aspects of attentional function are affected are, however, still to be determined. The primary aim of this investigation was to systematically examine the effects of experimentally induced pain on a range of attentional performance tasks. Following a review of tests of attentional disruption, seven best candidate tasks were selected and examined across seven experiments. The tasks were: continuous performance, flanker, endogenous precueing, n-back, inhibition, attentional switching, and divided attention. Healthy adult participants performed each of these tasks under three different conditions: a painful heat sensation, a warm heat sensation, and a nonheat control. Pain differentially affected attentional performance across these tasks; pain-related attentional impairment was found on the n-back, attentional switching, and divided attention tasks, but not on the other tasks. This finding suggests that the aspects of attention most affected by pain are those essential for the completion of complex tasks that require the processing of multiple cues and control over attentional deployment. These results are discussed in the context of an emerging view of pain as a demand for executive control and the development of measures that could be used to examine attentional disruption in the context of pain.
To establish a quantitative sensory testing (QST) profile in the trigeminal (V) area and test for site and gender differences in healthy humans.
A standardized QST protocol was applied on 15 healthy men (age range: 18 to 25 years old) and 15 age-matched women, and the sensitivity was examined bilaterally in facial sites supplied by the infraorbital (V2) and mental (V3) nerves. The cold detection threshold (CDT), cold pain threshold (CPT), warm detection threshold (WDT), heat pain threshold (HPT), thermal sensory limen (TSL), mechanical detection threshold (MDT), mechanical pain sensitivity (MPS), mechanical pain threshold (MPT), dynamic mechanical allodynia (ALL), windup ratio (WUR), pressure pain threshold (PPT), and vibration detection threshold (VDT) were determined. Data were tested with ANOVAs for repeated measures and post-hoc comparisons were calculated using Bonferroni tests.
There were significant gender differences with lower threshold (higher sensitivity) in women for CDT (P = .030) and PPT (P = .006). A significantly lower threshold (higher sensitivity) was detected for HPT (P < .001), and significantly higher thresholds (lower sensitivity) for VDT (P < .001) and CDT (P < .001) in V2 compared to V3. There were no significant right-to-left side differences for any of the QST parameters.
Application of this standardized QST protocol may allow for a better understanding of the underlying mechanisms from somatosensory phenotypes and provide basic information for the study of sensory dysfunctions in the V area.
The current study examined the relationship between pain-related fear, physical performance, and pain-related interference in the context of experimentally induced pain to the lower back. Thirty healthy participants completed a test of maximal trunk strength before and after induction of delayed-onset muscle soreness (DOMS) to the trunk extensors. Pain-related fear (Tampa Scale of Kinesiophobia and Pain Anxiety Symptom Scale) was assessed prior to DOMS induction, and measures of current pain and pain-related interference with life activities were obtained 1 day after DOMS induction. As predicted, pain-related fear was not related to strength production prior to DOMS induction. However, following DOMS induction, pain-related fear predicted reduced maximal strength production, individual decrement in maximal strength performance, and increased pain-related interference in life activities. Current pain intensity and anthropometric factors did not contribute significantly to these outcome measures. To our knowledge, this is the first study to identify the impact of pain-related fear on physical performance among a healthy group of individuals following experimental acute low back injury. The findings extend previous research on psychological variables and simulated injury, and suggest that pain-related fear may be an important vulnerability factor in development of disability following acute pain experience.
Two studies are reported that tested the fear-avoidance (FA) model using path analytic techniques. In study 1, 429 employees with back pain at baseline and back pain at 18 months follow-up completed questionnaires assessing sociodemographic information, pain severity, negative affect, pain-related fear, and disability. Results indicated that pain severity at baseline predicted pain-related fear and disability at follow-up, and that pain-related fear is rather a consequence than an antecedent of pain severity. Results further revealed that the disposition to experience negative affect has a low impact upon pain severity and disability, and is best viewed as a precursor of pain-related fear. Study 2 included 238 employees without back pain at baseline, but who developed back pain at 1 year follow-up. A similar model as in study 1 was tested. Overall, results are in line with those of study 1. Results are discussed in terms of theoretical relevance and clinical implications.
Unlabelled:
A number of negative affect-related constructs are important in pain. Some are general, such as anxiety, depression and negative affectivity, whereas others are more specifically pain-related (eg, fear of pain, pain anxiety, and pain catastrophizing). In addition, some more specific fear-related constructs, such as anxiety sensitivity, illness/injury sensitivity, and fear of negative evaluation have emerged as important to pain. Although these various constructs are considered conceptually separate, there is likely to be overlap between them. Since the extent of this overlap is unknown, the aim of the current study was to investigate these constructs in 1 sample in order to identify their common and unique features. Frequently used psychological measures were completed by 508 pain-free participants. Principal components analysis resulted in the extraction of three components: 1) General distress; 2) Fear of pain from injury/insult; and 3) Cognitive intrusion of pain. The results presented here suggest that there is indeed commonality between constructs, which may be due to either an overlap between items within measures or to close conceptual relatedness. The implications of these core dimensions are discussed with reference to future research and theory.
Perspective:
This article explores the relationships between various negative-affect pain-related measures and discusses the results from a principal components analysis. The findings show that some questionnaires may measure the same latent construct. A measure could be developed to measure these 3 core components more concisely for both clinical and research purposes.
There is a range of anxiety-related constructs associated with pain and pain-related disability. Those most often examined are pain catastrophizing, pain anxiety and anxiety sensitivity. All three are conceptualized to be important in the development and maintenance of chronic pain, and are included within fear avoidance models. Surprisingly these constructs are not routinely examined together, and when they are, have been investigated in healthy individuals using experimental techniques or patients with chronic conditions. Although these constructs are also thought to be important in acute clinical pain, they tend not to been examined together in the same study. The focus of the current research was therefore to examine these three anxiety-related constructs in an acute pain setting, and examine their relative influence on both pain and pain-related functional disability. Participants were 82 patients with a hand fracture, recruited from a fracture clinic at a general hospital. They completed a battery of measures related to anxiety, pain and disability. Once controlling for injury-related variables, catastrophizing was found to predict current pain, pain-related anxiety predicted task-related pain, whereas anxiety sensitivity was (negatively) associated with disability. These findings are discussed in light of the relative role that these anxiety-related constructs have in pain and disability, as well as implications for future research.
The primary purpose of this study was to analyze the sequential relationships proposed by the fear-avoidance model of pain [Vlaeyen JWS et al. The role of fear of movement/(re)injury in pain disability. J Occup Rehab 1995;5:235-52]. Specifically, this study evaluated whether early change in catastrophizing predicted late change in fear of movement, and whether these factors influenced post-treatment return-to-work. Secondary analyses tested relationships between (1) early change in catastrophizing, late change in depression, and disability; and (2) early change in catastrophizing, late change in pain severity, and disability. Analyses were conducted on a sample of 121 individuals (82 men and 32 women) with a work-related musculoskeletal injury, and high baseline catastrophizing and fear of movement scores. Participants were enrolled in a 10-week community-based disability management intervention, and they completed measures of catastrophizing, fear of movement, depression and pain severity at pre-, mid- and post-treatment. Return-to-work was assessed 4 weeks following termination of the intervention. Contrary to predictions, results from correlational analyses revealed non-significant relationships among indices of early change in catastrophizing and late changes in fear of movement, depression and pain severity. Multiple logistic regression analyses revealed that early change in catastrophizing, late changes in fear of movement and late change in pain severity were significant predictors of return-to-work, while late changes in depression were not. These findings highlight the importance of reductions in psychosocial risk factors in augmenting return-to-work outcomes. Implications for the fear-avoidance model and future research are discussed.
Background:
Psychological treatments are designed to treat pain, distress and disability, and are in common practice. This review updates and extends the 2009 version of this systematic review.
Objectives:
To evaluate the effectiveness of psychological therapies for chronic pain (excluding headache) in adults, compared with treatment as usual, waiting list control, or placebo control, for pain, disability, mood and catastrophic thinking.
Search methods:
We identified randomised controlled trials (RCTs) of psychological therapy by searching CENTRAL, MEDLINE, EMBASE and Psychlit from the beginning of each abstracting service until September 2011. We identified additional studies from the reference lists of retrieved papers and from discussion with investigators.
Selection criteria:
Full publications of RCTs of psychological treatments compared with an active treatment, waiting list or treatment as usual. We excluded studies if the pain was primarily headache, or was associated with a malignant disease. We also excluded studies if the number of patients in any treatment arm was less than 20.
Data collection and analysis:
Forty-two studies met our criteria and 35 (4788 participants) provided data. Two authors rated all studies. We coded risk of bias as well as both the quality of the treatments and the methods using a scale designed for the purpose. We compared two main classes of treatment (cognitive behavioural therapy(CBT) and behaviour therapy) with two control conditions (treatment as usual; active control) at two assessment points (immediately following treatment and six months or more following treatment), giving eight comparisons. For each comparison, we assessed treatment effectiveness on four outcomes: pain, disability, mood and catastrophic thinking, giving a total of 32 possible analyses, of which there were data for 25.
Main results:
Overall there is an absence of evidence for behaviour therapy, except a small improvement in mood immediately following treatment when compared with an active control. CBT has small positive effects on disability and catastrophising, but not on pain or mood, when compared with active controls. CBT has small to moderate effects on pain, disability, mood and catastrophising immediately post-treatment when compared with treatment as usual/waiting list, but all except a small effect on mood had disappeared at follow-up. At present there are insufficient data on the quality or content of treatment to investigate their influence on outcome. The quality of the trial design has improved over time but the quality of treatments has not.
Authors' conclusions:
Benefits of CBT emerged almost entirely from comparisons with treatment as usual/waiting list, not with active controls. CBT but not behaviour therapy has weak effects in improving pain, but only immediately post-treatment and when compared with treatment as usual/waiting list. CBT but not behaviour therapy has small effects on disability associated with chronic pain, with some maintenance at six months. CBT is effective in altering mood and catastrophising outcomes, when compared with treatment as usual/waiting list, with some evidence that this is maintained at six months. Behaviour therapy has no effects on mood, but showed an effect on catastrophising immediately post-treatment. CBT is a useful approach to the management of chronic pain. There is no need for more general RCTs reporting group means: rather, different types of studies and analyses are needed to identify which components of CBT work for which type of patient on which outcome/s, and to try to understand why.
Measurement of thermal pain thresholds is an essential part of quantitative sensory testing (QST). However, databases of QST show limitations due to large inter-individual variations including unreasonably low thresholds for thermal pain, lack of data on intra-individual variations over time and on the subjects' perception at threshold. This study sought to reduce inter-individual variations, investigated the reproducibility of measurements of thermal pain thresholds and included evaluation of thermally induced perceptions.
Thermal pain thresholds were investigated in 20 healthy subjects over three weeks using two protocols, one of which differed in making the subjects familiar with the likely range of applied temperatures beforehand. Both protocols included subjective ratings of pain and temperature perception at the pain thresholds.
Data obtain using both protocols showed large inter-individual variations, but small intra-individual variations of pain thresholds over time as well as good feasibility and reproducibility of subjects' ratings at threshold.
Previous experience of test stimuli has no influence on the variability of thermal pain thresholds. However, measurement of thermal pain thresholds showed good reproducibility over time. Evaluation of perception at thresholds provided further reproducible data.
Further approaches are needed to reduce variability of thermal pain thresholds; however, good reproducibility of thermal pain thresholds and thermally induced perceptions warrants consideration of their use in larger longitudinal studies.
Fear of pain has been implicated in the development and maintenance of chronic pain behavior. Consistent with conceptualizations of anxiety as occurring within three response modes, this paper introduces an instrument to measure fear of pain across cognitive, overt behavioral, and physiological domains. The Pain Anxiety Symptoms Scale (PASS) was administered to 104 consecutive referrals to a multidisciplinary pain clinic. The alpha coefficients were 0.94 for the total scale and ranged from 0.81 to 0.89 for the subscales. Validity was supported by significant correlations with measures of anxiety and disability. Regression analyses controlling for measures of emotional distress and pain showed that the PASS made a significant and unique contribution to the prediction of disability and interference due to pain. Evidence presented here supports the potential utility of the PASS in the continued study of fear of pain and its contribution to the development and maintenance of pain behaviors. Factor analysis and behavioral validation studies are in progress.
An experiment was conducted that investigated the effect of experimenter gender on the report of pain of male and female subjects. In order to evoke gender-related motives, experimenters were selected for their attractiveness. Subjects were asked to rate cold pressor pain in front of either a male or female experimenter. The results indicated that males reported significantly less pain in front of a female experimenter than a male experimenter. The difference in female subjects was not significant although they tended to report higher pain to the male experimenter.
How physicians approach patients and the problems they present is much influenced by the conceptual models around which their knowledge is organized. In this paper the implications of the biopsychosocial model for the study and care of a patient with an acute myocardial infarction are presented and contrasted with approaches used by adherents of the more traditional biomedical model. A medical rather than psychiatric patient was selected to emphasize the unity of medicine and to help define the place of psychiatrists in the education of physicians of the future.
This review is a critical summary of research examining gender variations in clinical pain experience. Gender-comparative pain research was identified through Medline and Psychlit searches and references obtained from bibliographies of pertinent papers and books. Review of this research demonstrates that women are more likely than men to experience a variety of recurrent pains. In addition, many women have moderate or severe pains from menstruation, pregnancy and childbirth. In most studies, women report more severe levels of pain, more frequent pain and pain of longer duration than do men. Women may be at greater risk for pain-related disability than men but women also respond more aggressively to pain through health related activities. Women may be more vulnerable than men to unwarranted psychogenic attributions by health care providers for pain. Underlying biological mechanisms of pain and the contribution of psychological and social factors as they contribute to the meaning of pain for women and men warrant greater attention in pain research.
Fear and/or anxiety about pain is a useful construct, in both theoretical and clinical terms. This article describes the development and refinement of the Fear of Pain Questionnaire (FPQ), which exists in its most current form as the FPQ-III. Factor analytic refinement resulted in a 30-item FPQ-III which consists of Severe Pain, Minor Pain, and Medical Pain subscales. Internal consistency and test-retest reliability of the FPQ-III were found to be good. Four studies are presented, including normative data for samples of inpatient chronic pain patients, general medical outpatients, and unselected undergraduates. High fear of pain individuals had greater avoidance/escape from a pain-relevant Behavioral Avoidance Test with Video, relative to their low fear counterparts, suggesting predictive validity. Chronic pain patients reported the greatest fear of severe pain. Directions for future research with the FPQ-III are discussed, along with general comments about the relation of fear and anxiety to pain.
Chronic pain syndromes such as chronic low back pain are responsible for enormous costs for health care and society. For these conditions a pure biomedical approach often proves insufficient. Numerous studies have shown that there is little direct relationship between pain and disability and suggest that the biopsychosocial approach offers the foundations for a better insight in how pain can become a persistent problem. The main assumption is that pain and pain disability are not only influenced by organic pathology, if found, but also by psychological and social factors. In this contribution, a behavioural analysis of chronic musculoskeletal pain will be discussed, with special attention to the role of pain-related fear in the development and maintenance of chronic pain disability, and the behavioural rehabilitation perspective of chronic pain management.
In an attempt to explain how and why some individuals with musculoskeletal pain develop a chronic pain syndrome, Lethem et al. (Lethem J, Slade PD, Troup JDG, Bentley G. Outline of fear-avoidance model of exaggerated pain perceptions. Behav Res Ther 1983; 21: 401-408).ntroduced a so-called 'fear-avoidance' model. The central concept of their model is fear of pain. 'Confrontation' and 'avoidance' are postulated as the two extreme responses to this fear, of which the former leads to the reduction of fear over time. The latter, however, leads to the maintenance or exacerbation of fear, possibly generating a phobic state. In the last decade, an increasing number of investigations have corroborated and refined the fear-avoidance model. The aim of this paper is to review the existing evidence for the mediating role of pain-related fear, and its immediate and long-term consequences in the initiation and maintenance of chronic pain disability. We first highlight possible precursors of pain-related fear including the role negative appraisal of internal and external stimuli, negative affectivity and anxiety sensitivity may play. Subsequently, a number of fear-related processes will be discussed including escape and avoidance behaviors resulting in poor behavioral performance, hypervigilance to internal and external illness information, muscular reactivity, and physical disuse in terms of deconditioning and guarded movement. We also review the available assessment methods for the quantification of pain-related fear and avoidance. Finally, we discuss the implications of the recent findings for the prevention and treatment of chronic musculoskeletal pain. Although there are still a number of unresolved issues which merit future research attention, pain-related fear and avoidance appear to be an essential feature of the development of a chronic problem for a substantial number of patients with musculoskeletal pain.
Sex-related differences in the experience of both clinical and experimentally induced pain have been widely reported. Specifically, females are at greater risk for developing several chronic pain disorders, and women exhibit greater sensitivity to noxious stimuli in the laboratory compared with men. Several mechanisms have been proposed to account for these sex differences. Psychosocial factors such as sex role beliefs, pain coping strategies, mood, and pain-related expectancies may underlie these effects. In addition, there is evidence that familial factors can alter pain responses, and these intergenerational influences may differ as a function of sex. Sex hormones are also known to affect pain responses, which may mediate the sex differences. Although the magnitude of these effects has not been well characterized, there are potentially important practical implications of sex differences in pain responses. These implications are discussed, and directions for future research are delineated.
Laboratory pain research has been criticized as being irrelevant to the clinical experience of pain. Previous findings have been inconsistent with some studies suggesting that experimental pain responses may be related to the reported presence or severity of chronic pain, while others report no such associations. However, few of these studies assess a variety of laboratory pain responses, and none has assessed relationships between clinical pain and diffuse noxious inhibitory controls (DNIC) in healthy subjects. We administered questionnaire measures of pain, quality of life, and psychological variables to a sample of healthy adults participating in a laboratory study of age differences in pain responses. DNIC was not related to other laboratory pain responses, psychological variables, or physiological variables measured in the present study. Regression models predicting health-related quality of life (e.g. pain, physical functioning) revealed that age, sex, and DNIC responses explained between 10 and 25% of the variance in these dependent measures. Of the laboratory pain variables, only DNIC was the sole consistent predictor of clinical pain and physical health, with greater DNIC responses related to less pain, better physical functioning, and better self-rated health. In addition, age differences in DNIC appeared to partially mediate age differences in physical functioning. These findings highlight the potential clinical relevance of experimental pain procedures and suggest that DNIC may be the laboratory pain response most closely associated with clinical pain and health-related variables.
Much evidence indicates that women experience painful stimuli as more intense than men do. Nevertheless, some data suggest that sustained low-level pain may be more disturbing to men than to women. The current experiment evaluated the hypothesis that pain is more disturbing for men than for women by comparing across genders sensory and emotional aspects of pain evoked by capsaicin. Ten men and 10 women (aged 20-46 years) received topical capsaicin for 30 min on the face in one session and on the ankle in another. The subjects rated on visual analog scales pain intensity, unpleasantness and anxiety each minute during capsaicin application and for 30 min after its removal. During capsaicin application, females rated both pain intensity (P = 0.04) and unpleasantness (P = 0.05) higher than did males. Further, subjects rated pain intensity and unpleasantness higher on the face than on the ankle, although the physical stimulus was the same. Despite their lower pain ratings, men reported more pain-related anxiety than women (P = 0.02) Moreover, men showed a significant positive correlation between anxiety and pain intensity and unpleasantness, whereas women did not. After removing the capsaicin, there was no overall effect of sex on either intensity (P = 0.18) or unpleasantness (P = 0.37) of the residual sensation. However, men still showed a positive correlation between anxiety and the intensity and unpleasantness of the sensation. Our data confirm with the topical capsaicin model that women rate pain higher than men, but despite their lower pain ratings, males have more anxiety related to pain.
Unlabelled:
Previous research has consistently shown moderate to large differences between pain reports of men and women undergoing experimental pain testing. These differences have been shown for a variety of types of stimulation. However, only recently have sex differences been demonstrated for temporal summation of second pain. This study examined sex differences in response to temporal summation of second pain elicited by thermal stimulation of the skin. The relative influences of state anxiety and gender role expectations on temporal summation were investigated. Asymptomatic undergraduates (37 women and 30 men) underwent thermal testing of the thenar surface of the hand in a temporal summation protocol. Our results replicated those of Fillingim et al indicating that women showed increased temporal summation compared to men. We extended those findings to demonstrate that temporal summation is influenced by anxiety and gender role stereotypes about pain responding. When anxiety and gender role stereotypes are taken into account, sex is no longer a significant predictor of temporal summation. These findings highlight the contribution of social learning factors in the differences between sexes' pain perception.
Perspective:
Results of this study demonstrate that psychosocial variables influence pain mechanisms. Temporal summation was related to gender role expectations of pain and anxiety. These variables explain a significant portion of the differences between men and women's pain processing, and may be related to differences in clinical presentation.
The aim of this study was to explore gender differences in anticipatory emotional distress, coping strategies, post-operative pain perception, and patient-controlled analgesia (PCA) use among adolescent surgical patients. One hundred and two 12-18-year-old adolescents undergoing surgeries with overnight hospital stay were recruited. Participants completed pre-operative measures of anxiety and anticipated pain. Post-operatively, they reported on coping skills, post-operative anxiety, and pain. Data on PCA use were recorded from medical records. Girls reported higher levels of pre-operative state anxiety and anticipated more pain. After surgery, girls and boys differed on their lowest daily pain ratings and average daily pain ratings, with girls reporting more pain in both cases. Reports of highest daily pain were similar across genders. Gender was found to moderate the relationship between anticipatory distress and post-operative pain, such that higher anticipatory distress before surgery predicted more post-operative pain for girls, but not for boys. Patterns of PCA use did not vary by gender on post-operative days 0 or 1. Findings suggest that adolescent boys' and girls' pain experiences are different in several important respects, although somewhat less divergent than has been reported in samples of adult males and females. Results have implications for the development of targeted intervention strategies to help adolescents cope effectively with acute post-operative pain.