Treatment Expectations-You Get What You Expect-and Depression Plays a Role.

Positive treatment expectations demonstrably shape treatment outcomes regarding pain and disability in patients with chronic low back pain. However, knowledge about positive and negative treatment expectations as putative predictors of interindividual variability in treatment outcomes is sparse, and the role of other psychological variables of interest, especially of depression as a known predictor of long-term disability, is lacking. We present results of the first prospective study considering expectations in concert with depression in a sample of 200 patients with chronic low back pain undergoing an inpatient interdisciplinary multimodal pain therapy. We analyzed the characteristics of pain and disability, treatment expectation, and depression assessed at the beginning (T0), at the end of (T1), and at 3-month follow-up (T2) of interdisciplinary multimodal pain therapy. Treatment expectations did emerge as a significant predictor of changes in pain intensity and disability, respectively, showing that positive expectations were associated with better treatment outcomes. Mediation analyses revealed a partially mediating effect of treatment expectations on the relation between depression and pain outcomes. PERSPECTIVE: These results expand knowledge regarding the role of treatment expectations in individual treatment outcome trajectories in chronic pain patients, paving the way for much-needed efforts toward optimizing patient expectations and personalized approaches in clinical settings.

The role of spontaneous vs. experimentally induced attentional strategies for the pain response to a single bout of exercise in healthy individuals.

OBJECTIVES: Exercise-induced pain and exercise-induced hypoalgesia (EIH) are well described phenomena involving physiological and cognitive mechanisms. Two experiments explored whether spontaneous and instructed mindful monitoring (MM) were associated with reduced exercise-induced pain and unpleasantness, and increased EIH compared with spontaneous and instructed thought suppression (TS) in pain-free individuals. METHODS: Eighty pain-free individuals participated in one of two randomized crossover experiments. Pressure pain thresholds (PPTs) were assessed at the leg, back and hand before and after 15 min of moderate-to-high intensity bicycling and a non-exercise control condition. Exercise-induced pain and unpleasantness were rated after bicycling. In experiment 1 (n=40), spontaneous attentional strategies were assessed with questionnaires. In experiment 2, participants (n=40) were randomly allocated to use either a TS or MM strategy during bicycling. RESULTS: In experiment 1, the change in PPTs was significantly larger after exercise compared with quiet rest (p<0.05). Higher spontaneous MM was associated with less exercise-induced unpleasantness (r=-0.41, p<0.001), whereas higher spontaneous TS was associated with higher ratings of exercise-induced unpleasantness (r=0.35, p<0.05), but not with pain intensity or EIH. In experiment 2, EIH at the back was increased in participants using instructed TS compared with participants using instructed MM (p<0.05). CONCLUSIONS: These findings suggest that spontaneous and presumably habitual (or dispositional) attentional strategies may primarily affect cognitive-evaluative aspects of exercise, such as feelings of exercise-induced unpleasantness. MM was related to less unpleasantness, whereas TS was related to higher unpleasantness. In terms of brief experimentally-induced instructions, TS seems to have an impact on physiological aspects of EIH; however, these preliminary findings need further research.

Pain and executive function: no association between remote exercise-induced hypoalgesia and cognitive inhibition in pain-free participants.

OBJECTIVES: Cognitive inhibition, which denotes the ability to suppress predominant or automatic responses, has been associated with lower pain sensitivity and larger conditioned pain modulation in humans. Studies exploring the association between cognitive inhibition and other pain inhibitory phenomena, like exercise-induced hypoalgesia (EIH), are scarce. The primary aim was to explore the association between cognitive inhibition and EIH at exercising (local) and non-exercising (remote) muscles after isometric exercise. The secondary aim was to explore the association between cognitive inhibition and pressure pain sensitivity. METHODS: Sixty-six pain-free participants (28.3 ± 8.9 years old, 34 women) completed two cognitive inhibition tasks (stop-signal task and Stroop Colour-Word task), a 3-min isometric wall squat exercise, and a quiet rest control condition with pre- and post-assessments of manual pressure pain thresholds at a local (thigh) and a remote site (shoulder). In addition, cuff pressure pain thresholds, pain tolerance and temporal summation of pain were assessed at baseline. RESULTS: No association was found between remote EIH and cognitive inhibition (Stroop interference score: r=0.12, [-0.15; 0.37], p=0.405, BF01=6.70; stop-signal reaction time: r=-0.08, [-0.32; 0.17], p=0.524, BF01=8.32). Unexpectedly, individuals with worse performance on the Stroop task, as indicated by a higher Stroop interference score, showed higher local EIH (r=0.33; [0.10; 0.53], p=0.007, BF01=0.29). No associations were observed between pain sensitivity and any of the cognitive inhibition performance parameters. CONCLUSIONS: The present findings do not support previous evidence on positive associations between exercise-induced hypoalgesia and cognitive inhibition, as well as baseline pain sensitivity and cognitive inhibition.

Patterns of Approach to Activity in 851 Patients With Severe Chronic Pain: Translation and Preliminary Validation of the 9-item Avoidance-Endurance Fast-Screen (AEFS) Into Danish.

OBJECTIVES: The Avoidance-Endurance Fast-Screen (AEFS) is a 9-item self-report questionnaire that classifies patients with back pain into 4 activity-related subgroups, based on the Avoidance-Endurance Model of pain. The objective of this study was to translate the AEFS into Danish and investigate its discriminative abilities in a large, diverse patient sample. MATERIALS AND METHODS: A total of 851 specialist care-seeking patients with severe chronic pain conditions participated in this cross-sectional study. Participants were categorized as showing a "distress-endurance" (DER), "eustress-endurance" (EER), "fear-avoidance" (FAR), or "adaptive" (AR) pattern. Principal component analysis reduced a large number of psychological variables beforehand. Construct and outcome-based validity were explored using multivariate analysis of variance. RESULTS: Of the participants, 33.6% were categorized as DER, 29.4% as EER, 22% as FAR, and 15% as adaptive. Principal component analysis showed the factors activity-related pain behavior, affective distress, and dysfunctional pain thoughts. The AEFS-DK discriminated all 4 subgroups in terms or their pain behavior with EER>DER>AR>FAR. FAR showed less moderate/vigorous activity than DER and EER and more sedentary time than EER. DER and FAR showed higher affective distress, dysfunctional pain thoughts, and poorer outcomes than AR and EER. CONCLUSION: The results indicate good construct validity of the AEFS-DK discriminating the 4 avoidance-endurance model-related subgroups with respect to approach to activity behavior, psychological variables, and reported physical activity. Concerning outcome-based validity, 2 subgroups DER/FAR and AR/EER could be distinguished with inconclusive results for the eustress-endurance subgroup. Future studies are warranted using longitudinal research designs investigating whether AEFS subgroups differ in terms of treatment effects and long-term prognosis.

Psychosocial subgroups in high-performance athletes with low back pain: eustress-endurance is most frequent, distress-endurance most problematic!

OBJECTIVES: In non-athletes, fear-avoidance and endurance-related pain responses appear to influence the development and maintenance of low back pain (LBP). The avoidance-endurance model (AEM) postulates three dysfunctional pain response patterns that are associated with poorer pain outcomes. Whether comparable relationships are present in athletes is currently unclear. This cross-sectional case-control study explored frequencies and behavioral validity of the AEM-based patterns in athletes with and without LBP, as well as their outcome-based validity in athletes with LBP. METHODS: Based on the Avoidance-Endurance Fast-Screen, 438 (57.1% female) young adult high-performance athletes with and 335 (45.4% female) without LBP were categorized as showing a "distress-endurance" (DER), "eustress-endurance" (EER), "fear-avoidance" (FAR) or "adaptive" (AR) pattern. RESULTS: Of the athletes with LBP, 9.8% were categorized as FAR, 20.1% as DER, 47.0% as EER, and 23.1% as AR; of the athletes without LBP, 10.4% were categorized as FAR, 14.3% as DER, 47.2% as EER, and 28.1% as AR. DER and EER reported more pronounced endurance- and less pronounced avoidance-related pain responses than FAR, and vice versa. DER further reported the highest training frequency. In athletes with LBP, all dysfunctional groups reported higher LBP intensity, with FAR and DER displaying higher disability scores than AR. CONCLUSIONS: The results indicate that also in athletes, patterns of endurance- and fear-avoidance-related pain responses appear dysfunctional with respect to LBP. While EER occurred most often, DER seems most problematic. IMPLICATIONS: Endurance-related pain responses that might be necessary during painful exercise should therefore be inspected carefully when shown in response to clinical pain.

Body Image in Athletes and Nonathletes With Low Back Pain: Avoidance-Endurance-Related Subgroups and Sports Status Play a Role.

CONTEXT: Low back pain (LBP) is a serious health problem, both in the general population as well as in athletes. Research has shown that psychosocial aspects, such as dysfunctional pain responses, play a significant role in the chronification of LBP. Recent research supports the relevance of the multidisciplinary concept of body image in the interpretation of LBP. OBJECTIVE: To examine the differences in 2 psychosocial aspects, body image and pain responses, between athletes and nonathletes with LBP. DESIGN: Cross-sectional design. SETTING: The questionnaires were distributed in the course of LBP treatment. PARTICIPANTS: Data from 163 athletes (mean age = 28.69 [9.6] y) and 75 nonathletes (mean age = 39.34 [12.63] y) were collected. INTERVENTIONS: Data were collected by questionnaires assessing body image, pain behavior, training activity, and LBP. MAIN OUTCOME MEASURES: To examine group differences between athletes and nonathletes regarding body image and pain behavior, the authors performed 2-way analyses of variance with Bonferroni post hoc tests. RESULTS: The results showed (1) a significant main effect regarding pain responses and body image, showing that participants with eustress endurance or adaptive pain behavior revealed a more positive body image in both groups compared with participants with distress endurance or fear-avoidance behavior, and (2) a significant main effect for the factor group in the body image dimension of physical efficacy, indicating a more positive body image for athletes. CONCLUSION: These results suggest that considering multiple risk factors for LBP, such as body image and dysfunctional pain behavior, as well as subgrouping, might be valuable for research and for broadening therapy options.

Overactivity in Chronic Pain, the Role of Pain-related Endurance and Neuromuscular Activity: An Interdisciplinary, Narrative Review.

OBJECTIVES: Decades of research have convincingly shown that fear of pain and pain-related avoidance behavior are important precursors of disability in daily life. Reduced activity as a consequence of avoidance, however, cannot be blamed for chronic disability in all patients. A contrasting behavior, pain-related dysfunctional endurance in a task and overactivity has to be considered. Currently, there is a need to better understand the psychological determinants of overactivity, dysfunctional endurance, and neurobiomechanical consequences. METHODS: This is a narrative review. RESULTS: The first part of this review elucidates research on self-reported overactivity, showing associations with higher levels of pain and disability, especially in spinal load positions, for example, lifting, bending, or spending too long a time in specific positions. In addition, measures of habitual endurance-related pain responses, based on the avoidance-endurance model, are related to objective assessments of physical activity and, again, especially in positions known to cause high spinal load (part 2). The final part reveals findings from neuromuscular research on motor control indicating the possibility that, in particular, overactivity and dysfunctional endurance may result in a number of dysfunctional adaptations with repetitive strain injuries of muscles, ligaments, and vertebral segments as precursors of pain. DISCUSSION: This narrative review brings together different research lines on overactivity, pain-related endurance, and supposed neuromuscular consequences. Clinicians should distinguish between patients who rest and escape from pain at low levels of pain, but who have high levels of fear of pain and those who predominantly persist in activities despite severely increasing pain until a break will be enforced by intolerable pain levels.

Pain Unstuck: The Role of Action and Motivation.

BACKGROUND: What is it that motivates our actions? As human beings, existing as part of complex societies, the actions we take are subject to multiple, often competing motives. Spanning non-conscious reflexes, cognitively derived choice as well as long- and short-term goals, our actions allow us to make sense of our environment. Pain disrupts action and hijacks our intentions. Whilst considered adaptive when temporary, pain that persists continues to interrupt and can threaten our ability to actively investigate a changing world. OBJECTIVE: This work is a narrative review. RESULTS: Drawing upon three complementary theoretical approaches to pain: an embodied framework, a motivational approach and the avoidance-endurance model, this review places the relationship between pain, motivation and action at its core, unpicking a dynamic process that can become stuck. CONCLUSIONS: In taking a wide view of pain and action, we expose the nuances within drive to goal behaviour in the presence of pain. This has implications for the clinic, specifically in relation to assessing the multifactorial influences that shape action in pain. But it also seeks to go further, considering the broader environment in which we make decisions and the influence that other professionals, outside of typical healthcare roles, may play a part in the maintenance and resolution of pain.

Assessing Endogenous Pain Inhibition: Test-Retest Reliability of Exercise-Induced Hypoalgesia in Local and Remote Body Parts After Aerobic Cycling.

OBJECTIVE: Acute exercise can trigger a hypoalgesic response (exercise-induced hypoalgesia [EIH]) in healthy subjects. Despite promising application possibilities of EIH in the clinical context, its reliability has not been sufficiently examined. This study therefore investigated the between-session and within-subject test-retest reliability of EIH at local and remote body parts after aerobic cycling at a heart rate-controlled intensity. METHODS: Thirty healthy adults (15 women) performed 15 minutes of aerobic cycling in two sessions. Pressure pain thresholds (PPTs) were assessed at the leg (local), the back (semilocal), and the hand (remote) before, immediately after, and 15 minutes after exercise. Intraclass correlation coefficients (ICCs) were calculated for absolute and percent changes in PPT from baseline to immediately postexercise, and between-session agreement of EIH responders was examined. RESULTS: PPTs significantly increased at the leg during both sessions (all P < 0.001) and at the back during session 2 (P < 0.001), indicating EIH. Fair between-session reliability was shown for absolute changes at the leg (ICC = 0.54) and the back (ICC = 0.40), whereas the reliability of percent changes was poor (ICC < 0.33). Reliability at the hand was poor for both absolute and percent changes (ICC < 0.33). Agreement in EIH responders was not significant for EIH at the leg or the back (all P > 0.05). CONCLUSIONS: Our results suggest fair test-retest reliability of EIH after aerobic cycling for local and semilocal body parts, but only in men, demonstrating the need for more standardized methodological approaches to improve EIH as a clinical parameter.

Exercise-Induced Hypoalgesia in Pain-Free and Chronic Pain Populations: State of the Art and Future Directions.

Exercise is considered an important component of effective chronic pain management and it is well-established that long-term exercise training provides pain relief. In healthy, pain-free populations, a single bout of aerobic or resistance exercise typically leads to exercise-induced hypoalgesia (EIH), a generalized reduction in pain and pain sensitivity that occurs during exercise and for some time afterward. In contrast, EIH is more variable in chronic pain populations and is more frequently impaired; with pain and pain sensitivity decreasing, remaining unchanged or, in some cases, even increasing in response to exercise. Pain exacerbation with exercise may be a major barrier to adherence, precipitating a cycle of physical inactivity that can lead to long-term worsening of both pain and disability. To optimize the therapeutic benefits of exercise, it is important to understand how EIH works, why it may be impaired in some people with chronic pain, and how this should be addressed in clinical practice. In this article, we provide an overview of EIH across different chronic pain conditions. We discuss possible biological mechanisms of EIH and the potential influence of sex and psychosocial factors, both in pain-free adults and, where possible, in individuals with chronic pain. The clinical implications of impaired EIH are discussed and recommendations are made for future research, including further exploration of individual differences in EIH, the relationship between exercise dose and EIH, the efficacy of combined treatments and the use of alternative measures to quantify EIH. PERSPECTIVE: This article provides a contemporary review of the acute effects of exercise on pain and pain sensitivity, including in people with chronic pain conditions. Existing findings are critically reviewed, clinical implications are discussed, and recommendations are offered for future research.

Pain-related avoidance and endurance behaviour in migraine: an observational study.

BACKGROUND: The role of avoidance and endurance behaviour is well established in chronic musculoskeletal pain, but less is known about its significance in migraine. METHODS: The Avoidance-Endurance Questionnaire behavioural subscales, the Pain Disability Index (PDI), the Migraine Disability Assessment Scale (MIDAS) and the Hospital Anxiety and Depression Scale (HADS) were obtained from 128 migraine patients (90 episodic, 38 chronic). Sixty nine of them were re-evaluated after 3-6 months. RESULTS: At baseline, there were positive relations between avoidance (especially social avoidance behaviour) and pain-related disability as assessed by the PDI (Wald χ2 [1] = 32.301, p < 0.001) and the MIDAS (Wald χ2 [1] = 14.387, p < 0.001). A negative relation of endurance behaviour with PDI scores did not survive multiple regression analysis. In addition, there was a positive relation of social avoidance with the HADS depression score (Wald χ2 [1] = 3.938, p = 0.047) and a negative relation of endurance (especially the humour-distraction subscale) with the HADS anxiety score (Wald χ2 [1] = 6.163, p = 0.013). Neither avoidance nor endurance were related to headache intensity or frequency, or to a diagnosis of episodic vs. chronic migraine. 3-6 months after treatment at our headache centre, headache frequency, intensity and pain-related disability were significantly improved (all p < 0.01) while avoidance and endurance were unchanged. CONCLUSIONS: This indicates that improvement in headache frequency and disability can be achieved in the absence of changes in avoidance or endurance behaviour. However, because of its significant link to headache-related disability, avoidance behaviour (especially social avoidance) should be investigated as a potential additional target of migraine therapy.

Body image is more negative in patients with chronic low back pain than in patients with subacute low back pain and healthy controls.

Background and aims Body image as an increasing research field has been integrated into pain research within the last years. However, research on cognitive-affective dimensions of body image dependent on different pain groups like acute/subacute and chronic pain patients, and healthy controls is still lacking. Therefore, this study aims to explore three dimensions of body image, namely self-acceptance, physical efficacy, and health in patients with low back pain and healthy controls. The present study is the first to distinguish between patients with low back pain in different stages of pain with regard to the concept of body image. In a second step we investigated the differences in exercise frequency between the three groups. Methods Seventy seven patients (53.2% female) suffering from low back pain and 57 healthy controls (42.1% female) filled in a battery of questionnaires in terms of body image, pain parameters and exercise frequency. Results Main results indicate first that patients suffering from chronic low back pain revealed a more negative body image in all three body image-dimensions than healthy controls. Second, patients suffering from subacute pain revealed a more negative body image of physical efficacy compared to the healthy controls. Conclusions Our results suggest that body image is relevant for the treatment of low back pain, because patients suffering from low back pain revealed a more negative body image than healthy controls. Implications To investigate the cognitive-affective dimensions of body image in different patient groups suffering from low back pain seems to be an important aspect for future research to improve therapy options and prevention of low back pain. Future research should also focus on improvements or on positive aspects of body image in patients with low back pain.

Exercise does not produce hypoalgesia when performed immediately after a painful stimulus.

BACKGROUND AND AIMS: Exercise-induced hypoalgesia (EIH) and conditioned pain modulation (CPM) are assumed to reflect descending pain inhibition. Potential interactions between EIH and CPM may be important in the therapy of chronic pain, as reduced CPM and increased pain after exercise are frequently observed. This study compared the EIH response after CPM was activated using a cold pressor task with the EIH response after a control condition. METHODS: Thirty-one participants (age: 27.7±9.8; 15 female) completed two sessions: a cold pressor task (CPT) session, i.e. testing EIH with preceding CPM activation induced using a 2 min CPT at approximately 2°C, and a control session, i.e. testing EIH after a control condition (2 min of quiet rest). EIH was induced using a 15 min bicycling exercise at a target heart rate corresponding to 75% VO2 max. Repeated measures ANOVAs on pressure pain thresholds (PPTs) at the hand, back and leg were used to determine the effects of exercise after the cold pressor test and control condition. Furthermore, correlations between CPM and EIH, in the CPT session as well as control session, were calculated at each assessment site. RESULTS: A significant time x condition interaction (F(1, 30)=43.61, p<0.001, partial η2=0.59), with Bonferroni-corrected post-hoc t-tests showed that PPTs increased after exercise in the control session (p<0.001), but not in the CPT session (p=0.125). Furthermore, there was a small positive correlation of EIH in the control session and CPM at the hand (r=0.37, p=0.043). There was a moderate negative correlation of EIH in the CPT session and CPM at the hand (r=-0.50, p=0.004), and smaller negative correlations at the back (r=-0.37, p=0.036) and at the leg (r=-0.35, p=0.054). CONCLUSIONS: Attenuated EIH after the CPM activation in comparison to a control condition suggests that EIH and CPM may share underlying pain inhibitory mechanisms on a systemic level. This assumption is further supported by the finding of small to moderate significant correlations between EIH and CPM at the hand. The attenuated EIH response furthermore suggests that these mechanisms are exhaustible, i.e. that its effects decline after a certain amount of inhibition. IMPLICATIONS: In patients with chronic pain, assessing the current capacity of the descending pain inhibitory system - as indicated by the CPM response - may aid to make better predictions about how patients will respond to exercise with respect to acute pain reduction.

Pain anxiety and fear of (re)injury in patients with chronic back pain: Sex as a moderator.

BACKGROUND AND AIMS: Anxiety and fear are increasingly seen as related, but distinct concepts, with anxiety describing a reaction to unclear or future threats, and fear to immediate threats. Anxiety and fear both play influential roles in pain. Yet, the two concepts have not been clearly distinguished in pain research. Their reported intensity differs between the sexes, and sex differences in the way pain anxiety and fear of (re)injury relate to pain intensity have been found separately in previous studies. However, they seem to be of a curious nature: In one study, pain anxiety was associated with elevated pain intensity in men, while in another, fear of (re)injury was associated with elevated pain intensity in women. This indicates a moderator effect of sex. The present study is the first to unite previous findings, and to show a more integrative picture, by examining and discussing this moderator effect of sex in a joint study of both pain-related anxiety and fear in both sexes. METHODS: In 133 patients (mean age 43.6 years, 62% female) with chronic low back pain (mean duration 7.7 years), sex differences were examined with correlations and a multiple linear regression analysis with interaction terms. Differences between subgroups of low and high anxiety/fear were explored via t-tests, following previous studies. RESULTS: Sex was supported as a moderator in the association of pain intensity with pain anxiety (PASS-20), and fear of (re)injury (TSK). Higher pain intensity was linked to higher pain anxiety only in men, and to higher fear of (re)injury only in women. A basic regression model with fear, anxiety, sex and disability as predictors (R2=.14, F(4,123)=3.24, p=.042) was significantly improved by the addition of the interaction terms Fear×Sex and Anxiety×Sex (R2=.18, F(2,121)=4.90, p=.001), which were both shown as significant predictors for pain intensity. Further t-tests revealed a significant difference in pain intensity between high and low anxiety in men (t(47)=-2.34, p=.023, d=-.43), but not in women. Likewise, a significant difference in pain intensity between high and low fear showed in women (t(80)=-2.28, p=.025, d=-.42), but not in men. CONCLUSIONS: The results support a moderator effect of sex and suggest differential mechanisms between the sexes in pain anxiety and fear in development and maintenance of back pain. The current study is the first to report and analyse this moderator effect. As potential underlying mechanisms, evolution and socialization are discussed, which may elucidate why fear might be more relevant for pain in women, and anxiety more relevant for pain in men. IMPLICATIONS: The results indicate the need for a more cautious conceptual separation of fear and anxiety in research. Future studies on fear and anxiety in pain should be aware of the distinction, in order to avoid reporting only half of the picture. The next step would be to solidify the results in different samples, and to examine whether a distinction between anxiety and fear in the sexes could have any benefit in pain treatment.

Gray matter alteration associated with pain catastrophizing in patients 6 months after lumbar disk surgery: a voxel-based morphometry study.

INTRODUCTION: Pain catastrophizing (PC), the increased attention to harmful aspects of pain (magnification), and the belief of low controllability (helplessness) has been shown to be important in the maintenance of pain. A growing research on structural alterations in chronic pain revealed an association between PC and brain areas that are involved in affective and cognitive pain processing. However, little is known about a differential effect of the components magnification and helplessness. OBJECTIVE: The aim of this study was to identify brain regions associated with overall PC and with the single components of magnification and helplessness. METHODS: We investigated 29 patients 6 months after lumbar disk surgery using voxel-based morphometry. Magnification and helplessness were assessed with subscales of the Avoidance-Endurance Questionnaire (AEQ); overall PC was computed using the sum score. The structural brain imaging data were preprocessed and analyzed using SPM8 and VBM8. Multiple regression analyses were performed with PC scales as predictors and depression as covariate. RESULTS: Pain catastrophizing was significantly associated with cortical gray matter in brain areas involved in processing attentional, sensory, and affective aspects of pain, including the left posterior cingulate cortex, supplementary motor area, and medial frontal gyrus. In addition, we provide preliminary evidence for brain structure association related to magnification and helplessness. CONCLUSION: This study provides evidence for PC-related structural alterations in patients with low back pain, which are consistent with findings from previous research in different chronic pain disorders. This study is the first to evaluate brain changes related to differential domains of PC.

Understanding Pain and Depression in Back Pain: the Role of Catastrophizing, Help-/Hopelessness, and Thought Suppression as Potential Mediators.

PURPOSE: The cognitive mediation hypothesis describes the influence of psychological factors on the relationship between pain and depression such as cognitions of catastrophizing and help-/hopelessness. More recent research also emphasizes the role of suppression of negative thoughts and experiences such as pain. However, there is little research investigating direct and indirect effects of these contrasting cognitions. METHOD: A total of 164 acute and sub-acute non-specific back pain patients participated in this study. Pain intensity, depression, and pain-related cognitions were measured using questionnaires, such as the Beck Depression Inventory and the Kiel Pain Inventory. Data were analyzed using structural equation modeling. RESULTS: The results of the path analysis support the hypothesis that cognitive coping strategies have a mediating effect on pain and depression. Consistent with previous research, we found that pain had no direct relation with depression. Help-/hopelessness had a direct path to depression, whereas catastrophizing had an indirect effect via increased help-/hopelessness. The current results also indicate that thought suppression mediated the relationship between pain and depression via both direct and indirect effects. CONCLUSION: Cognitive mediators, such as help-/hopelessness, catastrophizing, and thought suppression, have a significant impact on depression in patients with acute and sub-acute back pain. The current results may aid in the optimization of treatments for these patients by focusing attention toward the modification of dysfunctional cognitive pain-coping strategies.

Spanish Version of the Avoidance-Endurance Questionnaire: Factor Structure and Psychometric Properties.

To analyze the factorial structure and psychometric properties of the Spanish adaptation of the AEQ, and to validate it by reporting relevant pain-related variables, which were not investigated in the original study. One hundred and fifty Spanish patients diagnosed with chronic back and neck pain were referred by physicians from different pain clinics in Spain; all the patients filled out the questionnaires at their clinic. A series of principal components analyses (PCA) was performed to develop the Spanish version of the AEQ. Reliability and validity were also calculated. The PCAs revealed five fear-avoidance scales (Kaiser-Meyer-Olkin measures were between .60 and .88, and Bartlett's tests were significant, p .73) and suitable validity (p < .05). New results associated with pain-related cognitive/affective and behavioural responses are discussed. This instrument will probably help clinicians to identify Spanish patients at a high risk of chronicity and to develop treatments tailored to the different profiles in order to improve secondary and tertiary prevention in back and neck pain.

The German PASS-20 in patients with low back pain: new aspects of convergent, divergent, and criterion-related validity.

BACKGROUND: The PASS-20 (McCracken and Dhingra, Pain Res Manag 7:45-50, 2002) is a shortened version of the Pain Anxiety Symptoms Scale (PASS), a self-report measure of pain anxiety. The PASS-20 demonstrates good psychometric characteristics but has not yet been validated in a German population. PURPOSE: The aims of the present study were to (1) examine the factor structure and psychometric characteristics of the German PASS-20; (2) investigate its construct validity with respect to depression, fear-avoidance, and endurance; and (3) determine its criterion-related validity with a special emphasis on pain, disability, and quality of life. METHOD: A principal component analysis was performed on a sample (N = 195) of patients with acute, subacute, and chronic low back pain. Reliability was examined with Cronbach's α. Validity was assessed by correlating the PASS-20 to measures of depression, anxiety, disability, quality of life, and avoidance-endurance-related behavioral pain responses. RESULTS: The original four-factor structure proposed for the PASS-20 was replicated using the original subscale labels. The reliability of the total score and the subscales was satisfactory to excellent, and both convergent and divergent validity were moderate to high in the expected directions, showing positive correlations with anxiety, fear, depression, and fear-avoidance and negative correlations with endurance and quality of life. The PASS-20 showed unique predictive ability and advantages over the Tampa Scale of Kinesiophobia. CONCLUSIONS: The results for the German PASS-20 support the original factor structure and provide evidence of satisfactory psychometric characteristics and usefulness in patients with low back pain.

Associations between fear-avoidance and endurance responses to pain and salivary cortisol in the context of experimental pain induction.

Recent clinical studies in patients with lower back pain indicate that maladaptive fear-avoidance- and endurance-related pain responses (FAR and ER) have an influence on pain-induced physiological stress levels. The aim of the present study was to follow-up these results under well-controlled laboratory conditions. For this purpose, 30 healthy adults were asked to indicate their usual responses to pain, and were then confronted with an experimental pain stimulus (cold pressor test). Cortisol served as a measure of physiological stress. The results reveal positive associations between cortisol and FAR patterns, and negative associations between cortisol and behavioral ER. Conceivably, FAR contribute to long-lasting elevated stress levels in patients with stress-related musculoskeletal pain. In contrast, short-term, stress-lowering effects of ER might even be considered an advantage in coping with pain.