Affective and cognitive aspects in fibromyalgiathe roles of catastrophizing and acceptance

Résumé

ABSTRACT Fibromyalgia syndrome (FMS) is defined by the American College of Rheumatology as chronic (>3 months), widespread pain (axial plus upper and lower segment plus left and right sided pain) and tenderness in at least 11 of 18 tender points (Wolfe et al., 1990). Patients frequently describe sensations of fatigue, sleep disturbances, morning stiffness, symptoms associated with irritable bowel syndrome and affective distress, and the prognosis for symptomatic recovery is generally poor. When compared to patients with other chronic pain conditions, patients with FMS report higher levels of pain and functional disability and judge their quality of life as poorer (Burkhardt et al., 1993). Moreover, they make extensive use of health services, thus leading to high costs for medical and societal care (Penrod et al., 2004). The syndrome¿s pathology is not well understood, and to date, no treatment has proven effective in fully alleviating its symptoms. There is an agreement about the prevalence of FMS being approximately 2 to 3% (Wolfe et al., 1995), which represents approximately between 800.000 and 1.200.000 individuals in Spain. Indeed the prevalence of FM at the Rheumatologist surgery is around 12% (2.2% in men and 15.5% in women) (Valverde et al., 2000). Therefore, it is not surprising that in recent years, FMS has acquired greater significance and has become a first-order public health problem. There are several reasons for justifying this situation: (a) its high level of prevalence in the general adult population, (b) insufficient knowledge of its cause and the mechanisms that produce it (decrease of the nociceptive perception threshold), (c) absence of a curative treatment, and (d) dissatisfaction of patients and professionals with current therapeutic approaches (Ruiz et al., 2007; Soriano et al., 2000; Tornero & Vidal, 1999). Widespread pain, is the most frequent and incapacitating FMS symptom. The pathophysiology that produces pain and disability in fibromyalgia appears to involve a combination of central sensitization and nociceptive input. However there is no doubt nowadays that pain is a complex experience which involves several procedures. Indeed, pain has been defined by the International Association for the Study of Pain as ¿an unpleasant sensory and emotional experience associated with actual or potential tissue damage, or described in terms of such damage¿. Taking into account this global definition, the biopsychosocial model of pain has been considered as an appropriate approach. Biopsychosocial models describe the transition of acute to chronic pain, independent of a biomedical cause, as in FMS. In acute pain, three response systems are involved: behavioural reactions (eg, avoidance behaviour), cognitive reactions (eg, increased attention to bodily sensations and catastrophising) and physiological reactions (eg, an elevated autonomous arousal and muscle tension). All are appropriate adaptive short-term reactions to acute pain, but they become less functional and even detrimental when applied long term and in response to chronic pain (Flor et al., 1990). Avoidance behaviour has been described as an important aspect contributing to the aggravation of pain. This behaviour is affected by classic and operant learning processes, and is a prominent factor of the fear¿avoidance model (Vlaeyen et al., 1995). The key concept of the model is fear of pain following the sensation of acute pain¿for example, pain experienced during or after a road accident. People may react to this pain-related fear with avoidance or withdrawal of activities in order to prevent or escape pain. Cognitions such as the expectation that an activity will lead to pain or an increase in pain may also trigger avoidance behavior (Sharp, 2001). Avoidance behaviour is easily reinforced by the belief that one has successfully prevented increments in pain. As long as activities are avoided, it is impossible to refute the belief that activity will lead to pain. Long-lasting avoidance of activities can lead to changes in the musculoskeletal system caused by physical deconditioning and impairments in muscle coordination, also called the disuse syndrome (Bortz, 1984) The resultant deficient physical condition may in turn exacerbate the pain problem. Physiological reactions to pain such as heightened muscular tension and increased autonomic arousal may also lead to higher levels of pain and functional disability in the long term (Flor et al., 1990). Furthermore, this autonomic arousal could be interpreted as evidence of physical harm and subsequently lead to more avoidance behavior (Norton, 2003). This habitual pattern of physiological, behavioural and cognitive reactions to pain might be generalized to various other situations and areas independent of objective pathology and intensity of pain. Patients with high levels of avoidance behaviour have been shown to have a tendency to restrict their daily and social activities and withdraw from work, which will negatively affect long-term pain outcomes (Vlaeyen & Linton, 2000). Social factors, such as external reinforcements from the patient¿s social network, can further reinforce and maintain avoidance behaviour. In addition, avoidance may also include withdrawal from positive reinforcers such as leisure activities which in turn can exacerbate psychological distress and reduce their quality of life (Sharp, 2001). A vicious cycle has thus been established. Therefore, the main object for the psychological approaches consists in identifying which are the crucial psychological processes or constructs which are responsible for the avoidance behavior. Preventing individuals from getting stuck in their fears, will drive us to better prognosis. Two of the constructs that have shown to be relevant mediators in this area are catastrophizing and acceptance. Catastrophizing refers to a combination of negative thoughts and expectations regarding pain, and research shows that it is a critically important variable in understanding the experience of pain in rheumatologic disorders as well as other chronic pain conditions. It is also an important target for both psychosocial and pharmacological treatment of pain due to its relevant influence in a negative prognosis (Sullivan et al., 2001). The construct of catastrophizing incorporates magnification of pain-related symptoms, rumination about pain, feelings of helplessness, and pessimism about pain-related outcomes and it is typically measured using a self-report inventory, the Pain Catastrophizing Scale (PCS) (Sullivan et el., 1995). Although individuals are sometimes dichotomized as catastrophizers and noncatastrophizers, most research treats catastrophizing as a continuous, normally distributed variable (Sullivan et al., 2001). A rich area of debate has centered on whether catastrophizing is best conceptualized as a stable and enduring trait, such as a dimension of personality, or as a modifiable characteristic (Jensen et al., 2001; Smeets et al., 2006), with some evidence supporting both positions. Catastrophizing has been correlated with adverse outcomes such as pain severity, pain sensitivity, depression and disability. Concerning hypothesized mechanisms of action, several alternatives has been proposed such as catastrophizing interferes with pain-coping and beneficial behaviors, increases attention to pain, amplifies pain processing in the CNS or catastrophizing has a maladaptive impact on the social environment. However, the effects of catastrophic thoughts on patient functioning presumably rely not only on their content or frequency, but also on the experiences and current circumstances of the person having them. For example, behavior disruptions and suffering from catastrophic thoughts are more likely to occur when they overwhelm other potential influences on behavior and limit response choices, such as when they lead to exaggerated emotional responses and unnecessary avoidance. On the other hand, everyone, including those who suffer with chronic pain, has likely had the experience of having a catastrophic thought but dismissing it as unimportant or of no particular concern. Therefore, there is a need for analyses of the processes by which catastrophic thinking exerts its behavioral and emotional impact. Emerging psychological theories discuss acceptance in relation to effects of the experience of aversive thoughts, moods, or sensations (Hayes, Strosahl, & Wilson, 1999). Acceptance entails having contact with painful or discouraging experiences without some of their added influences on behaviors, particularly influences that lead to unnecessary avoidance, limit participation in life, or impede the pursuit of important goals (Hayes et al., 1999; McCracken, 1998, 2005). With regard to chronic pain, this line of reasoning suggests that sensations of pain, even when intense, need not inhibit success at living a meaningful life, nor do they need to be fought against, ignored, suppressed, or conquered before success can occur. The construct of acceptance of pain is based on two components (activities engagement and pain willingness) and it is typically measured using the Chronic Pain Acceptance Questionnaire (CPAQ) (McCracken et al., 2004b). Although the notion that it is possible to live with these difficult and distressing aspects of chronic pain is somewhat counterintuitive, there is increasing supportive evidence for acceptance of chronic pain. In clinical samples acceptance of pain is associated with less pain, distress, disability (McCracken, 1998; McCracken et al., 2004a), and greater psychological wellbeing (Viane et al., 2003). In treatment outcome studies acceptance-based methods are associated with improved emotional, psychosocial and physical functioning, and reduced healthcare use (Dahl et al., 2004;McCracken et al., 2005; Wicksell et al., 2007; Vowles et al., 2008). The final goal of the Acceptance-based interventions is to prevent the experiential avoidance promoting the psychological flexibility through the use of diverse components such as acceptance, contact with the present moment, values-based action, committed action, self-as-context, and cognitive defusion (Hayes et al., 1999; Hayes et al., 2006). All of them, encourage clients to make willing contact with aversive psychological content altering the relationship between pain-related cognitions and overt behavior. As a result, the person is taught how to go ahead having thoughts and not being entangled in thoughts. AIMS OF THE RESEARCH As we mentioned previously, FMS has become a first-order public health problem. Catastrophizing and acceptance seem to be relevant psychological constructs in the field of chronic pain but there is hardly any manuscript addressing their relationship among individuals diagnosed with FMS. For that, the aims are: 1) To validate the Pain Catastrophizing Scale (PCS) and the Chronic Acceptance Questionnaire (CPAQ) into Spanish in an FMS sample and assess their associations and correlations with several sociodemographic and outcomes measures. 2) Regarding Catastrophizing: a. It has been proposed that the development of FMS involves an interaction between the experience of pain and catastrophizing, but it is unclear when and how this cognitive construct first becomes important. Consequently, there is a need to study the relationship between catastrophizing and dysfunction in relation to the development of FMS. We use cross-sectional comparisons where different stages of chronicity provide a proxy for the development process. b. It is also unclear whether the three components of catastrophizing (rumination, magnification, and helplessness) contribute equally to the prediction of dysfunction in FMS or whether certain components are more predictive than others. Information concerning the relative importance of the components of catastrophizing could help treatment providers to tailor interventions to facilitate positive outcomes. 3) Regarding Acceptance of pain: a. It has been established that the coping behavioural strategies are valuable in predicting important aspects of patient wellbeing and functioning. However, it is expected that acceptance of pain measures, accounted for even more variance in the outcomes scores. Therefore, acceptance will show a greater utility in comparison with the behavioural coping strategies b. The findings will also allow us to observe differences between acceptance and behavioural strategies and to elucidate the targets of intervention in FMS patients. METODOLOGY Design: A multi-center, cross-sectional study. Participants: To be included in the study, patients were required to fulfill several inclusion criteria: (1) be between 18 and 65 years old; (2) be able to understand and read Spanish; (3) meet the American College of Rheumatology criteria for primary FMS; and (4) have been diagnosed by a Spanish National Health Service rheumatologist. Exclusion criteria included the following: (1) diagnosis of a severe Axis I psychiatric disorder (dementia, schizophrenia, paranoid disorder, or abuse of alcohol and/or drugs) or a severe Axis II disorder; and (2) refusal to participate. Primary outcomes: A) Pain Catastrophizing Scale (PCS) The PCS is a 13-item scale designed to assess the catastrophizing cognitions of individuals by asking them to reflect on thoughts or feelings associated with current painful experiences (Sullivan et al., 1995). The PCS can be subdivided into three subscales: rumination, magnification and helplessness. Its validity and reliability have been previously reported. Our group was responsible for validating the Spanish version of this questionnaire (García-Campayo et al., 2008). There is no established "cut-off" point because pain catastrophizing is considered a personality trait distributed in a continuous way in the general population. B) Chronic pain acceptance questionnaire (CPAQ) The CPAQ was originally a 34-item measure of acceptance of pain. All items of the CPAQ are rated on a 0 (never true) to 6 (always true) scale. Based on recent analyses the CPAQ has been shortened to 20 items and now yields scores for two subscales, derived from factor analysis: Activity Engagement and Pain Willingness (McCracken et al., 2004b). Following the scoring procedure, a single total score was calculated based on the nine reverse-keyed items measuring pain willingness and the other eleven items measuring activities engagement. The maximum possible total score is 120, with a higher score indicating better acceptance. The Spanish version of the CPAQ, has been validated by our team and achieves adequate reliability (Rodero et al., 2010). Secondary outcomes A) Demographic and Pain-Related Variables Each participant was interviewed and provided information about a number of demographic and pain-related variables including age, work status, time diagnosed with FMS, medications and other medical treatments. B) Pain Visual Analogue Scale (PVAS) The PVAS was designed to allow a subjective assessment of pain. It consists of a 10 cm long straight line whose tips represent the limits of pain intensity ("No pain" to "maximum pain ever experienced"). The patients estimated the pain intensity experienced on the same day between 0 and 100. Previous studies have demonstrated PVAS to have adequate psychometric properties (Huskisson et al., 1993). C) Fibromyalgia Impact Questionnaire (FIQ) The (FIQ) is a 10-item self-report questionnaire developed to measure the health status of fibromyalgia patients (Burckhardt et al., 1991). The first item focuses on patients' ability to perform physical activities. The next two items ask patients to circle the number of days in the past week that they felt good and how often they missed work. The remaining seven items concern the ability to work, pain, fatigue, morning tiredness, stiffness, anxiety, and depression and are measured with the visual analogue scale (VAS). This instrument has a translated and validated Spanish version (Rivera et al., 2004). D) Physical symptoms The number of comorbid physical symptoms was obtained from a standardised symptom checklist (Casanueva, 2009). This self-report checklist instructs participants to indicate whether they experienced each of the 75 symptoms for at least 3 months over the past year. A score was obtained by totalling the affirmative responses to all 75 symptoms. Sample symptoms include dry eyes, shortness of breath, dizziness, irregular heartbeat, tingling in the extremities, urinary urgency, and coughing spells. E) Medical Outcome Study Short Form 36 (SF-36) The Medical Outcome Study Short Form 36 (SF-36) is a 36-item instrument designed to measure general health status and health-related quality of life (Ware et al., 1992). One item assesses perceived change in health status, while 35 items examine eight generic domains in both physical and mental health. The eight domains include Physical Function, Physical Role, Bodily Pain, General Health,Vitality, Social Function, Emotional Role and Mental Health. Scores in each subscale range from 0 to 100 with higher scores indicating better health status. The Spanish version of SF-36 has been shown to be reliable with good construct validity (a = 0.78-0.96) (Alonso et al., 1995). F) The Chronic Pain Coping Inventory - 42 (CPCI-42) The Chronic Pain Coping Inventory (CPCI) (Jensen et al., 1995) was originally a 65-item self-report questionnaire; based on recent analyses, it has been shortened to 42 items (Romano et al., 2003). It asks patients to rate the frequency of use of behavioural and cognitive strategies over the previous week. It has the same CPCI-65 strategies, which are grouped into the following eight subscales: Guarding, Resting, Asking for Assistance, Relaxation, Task Persistence, Exercise/Stretch, Seeking Social Support and Coping Self-Statements. This instrument was translated and validated into Spanish by our team. Reliability coefficients were adequate based on the current data (a = 0.65-0.82) and test-retest reliability (intraclass correlation coefficient 0.76) (García-Campayo et al., 2007). G) Hospital Anxiety and Depression Scale (HADS) The HADS (Zigmound et al., 1983) is a self-report scale designed to screen for the presence of depression and anxiety disorders in medically ill patients. It comprises 14 items that are rated on a 4-point Likert-type scale, and it is appropriate for use in community and hospital settings. Two subscales assessed depression and anxiety independently (HADS-Dep and HADS-Anx, respectively).This has been validated in a Spanish sample (Tejero et al., 1986). HADS was selected for use in the present study as it is considered to be one of the best questionnaires for assessing depression and anxiety in patients with pain disorders. Statistical analyses: 1 Spanish validation of the Pain Catastrophizing Scale (PCS) and the Chronic Pain Questionnaire (CPAQ) Both followed the same steps. In order to determine the suitability of the data for principal components analysis, the Kaiser-Meyer-Olkin Measure of Sampling Adequacy and Bartlett's Test of Sphericity were calculated. The dimensionality of the scale and the questionnaire were inspected with a Principal Components Analysis (PCA) followed with oblique (direct oblimin) rotation to permit correlations among factors. The criterion validity was examined by calculating the correlations between the Spanish PCS and CPAQ scores and the other questionnaires, using Pearson's r correlation coefficient. We also examined the association among the questionnaires scores and the socio-demographic and clinical characteristics of the sample, applying correlational analyses for the association with continuous variables (age and pain duration) and non-parametric tests (Mann-Whitney or Kruskal¿Wallis) for categorical data (gender, marital status, educational level, and work status). Internal consistency was determined using Cronbach's alpha and item-total correlation coefficients. Test-retest reliability, evaluated with the intraclass correlation coefficient, was assessed for the 1- to 2-week follow-up interval, during which time the patients did not change baseline treatment 2 Assessing the influences of the Catastrophizing and Acceptance in fibromyalgia patients In the descriptive analysis of the samples, means and standard deviations were calculated for continuous variables (i.e., age and pain), and percentages were calculated for categorical variables (i.e., gender and treatment setting). Analysis of variance (ANOVA) was used to compare the different groups. Pearson correlations were used to assess the relationship between the two main psychological constructs (catastrophizing and acceptance) and other psychometric variables such as pain intensity, global functioning, anxiety and depression. Finally, a hierarchical regression analysis was performed to determine the effects of the catastrophizing and acceptance on fibromyalgia patients. All analyses were conducted with SPSS 15. CONTRIBUTIONS OF PhD CANDIDATE 1 The validation of two questionnaires used throughout the world, and furthermore in a disorder as prevalent as FMS, will be invaluable for monitoring the effectiveness of treatments. 2 There are many studies on vulnerability factors associated with the disability of patients. This research will also allow us to know the vulnerability due to contextual factors. 3 The results will further allow us to observe the differences between the components of acceptance (activities engagement and pain willingness) and other coping strategies, and thus clarify the intervention objectives. 4 The identification of their unique contributions of processes and how these processes may interact to affect patient functioning will: o Improve research on FMS to be able to identify psychological constructs relevant to the disease. o Guide psychological treatment to the development of more effective constructs to improve the quality of life and function of patients with fibromyalgia. Currently, psychological approaches in FMS are considered the most effective and cost-effective. CONCLUSION 1. Validation process: Both psychometric properties of the Spanish validated versions of the Pain Catastrophzing Scales and the Chronic Pain Acceptance Questionnaire, are adequate. The Scree plot indicated the same number of factor to the original English versions. Principal Components with Varimax Rotation revealed a satisfactory percentage of Total Variance explained by the two psychological constructs. Looking at the Component Matrix, individual items could be allocated to the same subscales as they were in the English version. Therefore, construct validity of the translated versions can be supported. 2. Regarding Catastrophizing: 2.1 The influence of catastrophizing on global functioning in fibromyalgia patients is variable and dependent on the context (i.e., duration of diagnosis) in which the catastrophizing thoughts occur. Therefore, this issue should be taken into account by tailoring psychological interventions. 2.2 Specifically, regression analyses revealed that rumination accounted for significant unique variance in FM impact in the group of patients who had been diagnosed with FMS for less than 2 years; Magnification and helplessness predicted FM impact over and above the variance accounted for pain severity for patients who had been diagnosed for 2-4 years, and helplessness was the strongest predictor of FM impact in the group of patients diagnosed for more than 4 years. 2.3 Catastrophizing was a stronger predictor of global functioning than pain itself for the three different stages of chronicity and that catastrophizing remained constant over time, despite the fact that fibromyalgia impact increased. 2.4 These findings suggest that not only is the type of intervention important but also the timing of the treatment. The findings accentuate the significance of early detection and treatment of patients who are at risk of developing fibromyalgia and related problems. Intervening early in the course of a pain condition may help prevent maladaptive patterns of pain coping and illness behaviours that are resistant to treatment, and it may have the potential to reduce or prevent the negative impacts of fibromyalgia that, in turn, will reduce societal and medical costs. 2.5 If patients with fibromyalgia were to be subdivided consistent with their distinctive contextual cognitive and behavioural patterns, and if interventions were subsequently modified to match these specific risk profiles, the efficacy of psychological treatment programs could be substantially advanced 3. Regarding Acceptance: 3.1 Acceptance of chronic pain predicted adjustment to chronic pain better than behavioural coping strategies in fibromyalgia patients. 3.2 A greater acceptance of chronic pain in fibromyalgia patients was associated with less pain, symptoms, fibromyalgia impact, anxiety, and depression as well as with better general health, vitality and physical and social functioning. 3.3 Our results found that most of the behavioural coping strategies showed types of patient behaviour that lead to more suffering and poor functioning. In turn, acceptance of pain components, showed the types of patient behaviour that lead to less suffering and better functioning 3.4 The coping behaviours strategies often targeted within psychological treatments have not been shown to be related to outcomes as predicted. Additionally, acceptance measures may offer more utility in guiding treatment. 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