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Pain Medicine 2014; *: **–** Wiley Periodicals, Inc.
Attentional Bias Toward Negative Information in Patients with Fibromyalgia Syndrome
Stefan Duschek, PhD,* Natalie S. Werner, PhD,† Nils Limbert,* Andreas Winkelmann, MD,‡ and Pedro Montoya, PhD§ *Institute of Applied Psychology, UMIT, University for Health Sciences Medical Informatics and Technology, Hall in Tirol, Austria; Departments of †Psychology and ‡
Physical Medicine and Rehabilitation, University of Munich, Munich, Germany; §
Department of Psychology, University of the Balearic Islands, Palma de Mallorca, Spain Reprint requests to: Stefan Duschek, PhD, UMIT—University for Health Sciences, Medical Informatics and Technology, Eduard-WallnöferZentrum 1, A-6060 Hall in Tirol, Austria. Tel: +43 50 8648 3825; Fax: +43 50 8648 67 3825; E-mail: [email protected]. No conflicts of interest have to be disclosed. The work was partially funded by the Spanish Ministry of Economy and Competitiveness and European Regional Development Funds (Grant #PSI2010-19372 to Pedro Montoya).
Abstract Objective. In addition to central nervous sensitization, affect dysregulation constitutes an important factor in the pathogenesis of fibromyalgia syndrome (FMS). The present study is concerned with emotional influences on information processing in FMS. The hypothesis of attentional bias, i.e., selective processing of negatively connoted stimuli, was tested. Methods. Twenty-seven female FMS patients and 34 healthy women undertook an emotional modification of the Stroop task. Subjects had to decide whether the colors of positive, negative, and neutral adjectives accorded with color words presented in
black. Attentional bias was defined as delay in color naming of emotional words relative to neutral words. Affective and anxiety disorders, pain severity, as well as medication were considered as possible factors mediating the expected interference. Results. Patients showed marked attentional bias, manifested in a greater response delay due to negative words compared with the control group. Among the clinical features, pain severity was most closely associated with the extent of the interference. While depression played only a subordinate role, anxiety and medication were without effect. Conclusions. The study provides evidence of emotionally driven selective attention in FMS. Attentional bias to negative information may play an important role in the vicious circle between negative affective state and pain augmentation. In the management of FMS pain, strategies aiming at conscious direction of attention may be helpful, e.g., imagery techniques or mindfulness training. Key Words. Fibromyalgia; Chronic Pain; Emotion; Selective Attention; Emotional Stroop Test
Introduction Fibromyalgia syndrome (FMS) is a chronic condition of widespread pain accompanied by symptoms such as morning stiffness, depression, fatigue, sleep disturbance, and impaired mental functioning [1]. According to current knowledge, hyperalgesia occurs due to hypersensitivity of central nociceptive pathways and deficient pain-inhibiting mechanisms [2]. Affective modulation of the processing of pain-related information has also been implicated in FMS pathology [3,4]. This is supported by neuroimaging studies showing more pronounced hyperactivity of brain areas mediating affective pain processing than of structures related to sensory pain [5–7]. It has been hypothesized that FMS patients are particularly vulnerable to the effects of negative mood, in the sense that pain potentiation during experiences of sadness, anxiety, or disgust may be stronger than in healthy individuals [8–10]. Further aberrances in emotion processing include impaired affect 1
Duschek et al. balance, difficulties in emotion recognition as well as increased emotional avoidance, catastrophizing, and alexithymia [11–15]. The present study is concerned with emotional influences on information processing in fibromyalgia. Attentional bias in terms of selective processing of negative information is believed to play an important role in psychopathology [16]. Enhanced attention toward threatening or general negative cues was reported for instance, in depression, anxiety disorders, posttraumatic stress, and personality disorders [17–21]. Selective attention to emotionally relevant stimuli interferes with information processing by capturing processing resources, thereby disrupting ongoing cognitive activity. This effect is most frequently studied using the Emotional Stroop Test. In this experimental paradigm, a subject is asked to name the colors of words with different emotional contents while ignoring the word meaning. Attentional bias is reflected by longer time to name the color of emotional as compared with neutral words of comparable frequency in everyday speech. A large number of studies have documented the fact that individuals with psychiatric disorders exhibit decelerated color naming of words with general negative connotations, or expressions specifically related to their diseases [16].
healthy control group, manifested in longer color naming times for negative with respect to neutral words. No group difference was expected for interference regarding the positive words. Due to the complex nature of fibromyalgia and its overlap with other disease entities, it seemed worthwhile in the present study to also investigate the contribution of specific features of FMS pathology to the expected attentional bias. For this purpose, psychiatric comorbidity was diagnosed, and clinical questionnaires on pain severity, depression, and anxiety were applied. We focused on depression and anxiety because of their high prevalence in FMS and also in consideration of reports on attentional bias in patients suffering from affective and anxiety disorders [18,20,21].
Methods Participants
In the field of chronic pain, the Emotional Stroop Test has mainly been used to investigate the hypothesis of hypervigilance to pain, i.e., unintentional attention toward pain-related information, which has been suggested to be relevant in the appearance of the disorder [22,23]. A recently published meta-analysis, which included 22 studies based on the Emotional Stroop Test, confirmed the occurrence of this effect but also alluded to its relatively small size and limited robustness [24]. To date, only a single study applied the Emotional Stroop Test in fibromyalgia research [25]. Here, patients and healthy subjects had to name the colors of words describing typical symptoms of FMS as well as disease-unrelated words with positive, negative, or neutral connotations. Patients showed significantly longer response times to the words from all categories, which was interpreted as indicative of general hypervigilance in FMS, i.e., a patients’ propensity to focus on task-irrelevant information.
Twenty-seven female FMS patients with a mean age of 52.7 years (SD = 9.2 years) participated in the study. They were recruited via interdisciplinary treatment programs for chronic pain patients, self-regulating communities, and the German Fibromyalgia Association. The patients were examined either by an anesthesiologist or specialist in pain medicine, and met the American College of Rheumatology criteria for FMS [28]. Exclusion criteria for participation comprised inflammatory causes of pain, neurological disorders, metabolic abnormalities, and severe somatic (e.g., cancer) or psychiatric (e.g., psychosis) diseases. Mean illness duration, i.e., the interval from first diagnosis of FMS, was 6.0 years (SD = 5.6 years). Tender point testing revealed an average of 15.3 active tender points (SD = 2.8). Sixteen (59.3%) patients were diagnosed with comorbid depression and four (14.8%) with comorbid anxiety disorders (panic disorder, generalized anxiety disorder, or phobias). At the time of assessment, eight (29.6%) patients were being treated with antidepressants, nine (33.3%) were using nonopioid analgesics, two (7.4%) opiates, and one (3.7%) anxiolytics. Mean time of education, which was taken as an estimate of educational background, was 13.7 years (SD = 3.1 years).
In the current study, a variant of the Emotional Stroop Test was applied in order to investigate the hypothesis of selective processing of affectively negative information in FMS. The presence of a negative attention bias seems plausible taking into account the aforementioned affective dysregulation such as disturbed affect balance and high levels of catastrophizing [11,12]. In addition, fibromyalgia exhibits high comorbidity with affective and anxiety disorders, and the patients display considerable elevations in self-report scales of depression and anxiety [8,26,27]. The Emotional Stroop Test included positive, negative, and neutral adjectives. In accordance with the reasoning presented above, we predicted greater selective attention toward negative cues in FMS patients with respect to a
The control group included 34 healthy women with a mean age of 53.9 years (SD = 8.4 years), who were recruited from local institutions for adult education and via personal contacts. Control subjects met the same exclusionary criteria as did the patients but were additionally required not to have any pain disorders. None of the control subjects were diagnosed with depression or anxiety disorders. None of them used antidepressants, analgesics, anxiolytics, or opiates. Mean time of education in the control group was 13.8 years (SD = 2.5 years). The patient and control groups did not differ significantly in terms of age (F [1,59] = 0.38, P = 0.56, partial eta squared
Pain Medicine 2014; *: **–** Wiley Periodicals, Inc.
Attentional Bias Toward Negative Information in Patients with Fibromyalgia Syndrome
Stefan Duschek, PhD,* Natalie S. Werner, PhD,† Nils Limbert,* Andreas Winkelmann, MD,‡ and Pedro Montoya, PhD§ *Institute of Applied Psychology, UMIT, University for Health Sciences Medical Informatics and Technology, Hall in Tirol, Austria; Departments of †Psychology and ‡
Physical Medicine and Rehabilitation, University of Munich, Munich, Germany; §
Department of Psychology, University of the Balearic Islands, Palma de Mallorca, Spain Reprint requests to: Stefan Duschek, PhD, UMIT—University for Health Sciences, Medical Informatics and Technology, Eduard-WallnöferZentrum 1, A-6060 Hall in Tirol, Austria. Tel: +43 50 8648 3825; Fax: +43 50 8648 67 3825; E-mail: [email protected]. No conflicts of interest have to be disclosed. The work was partially funded by the Spanish Ministry of Economy and Competitiveness and European Regional Development Funds (Grant #PSI2010-19372 to Pedro Montoya).
Abstract Objective. In addition to central nervous sensitization, affect dysregulation constitutes an important factor in the pathogenesis of fibromyalgia syndrome (FMS). The present study is concerned with emotional influences on information processing in FMS. The hypothesis of attentional bias, i.e., selective processing of negatively connoted stimuli, was tested. Methods. Twenty-seven female FMS patients and 34 healthy women undertook an emotional modification of the Stroop task. Subjects had to decide whether the colors of positive, negative, and neutral adjectives accorded with color words presented in
black. Attentional bias was defined as delay in color naming of emotional words relative to neutral words. Affective and anxiety disorders, pain severity, as well as medication were considered as possible factors mediating the expected interference. Results. Patients showed marked attentional bias, manifested in a greater response delay due to negative words compared with the control group. Among the clinical features, pain severity was most closely associated with the extent of the interference. While depression played only a subordinate role, anxiety and medication were without effect. Conclusions. The study provides evidence of emotionally driven selective attention in FMS. Attentional bias to negative information may play an important role in the vicious circle between negative affective state and pain augmentation. In the management of FMS pain, strategies aiming at conscious direction of attention may be helpful, e.g., imagery techniques or mindfulness training. Key Words. Fibromyalgia; Chronic Pain; Emotion; Selective Attention; Emotional Stroop Test
Introduction Fibromyalgia syndrome (FMS) is a chronic condition of widespread pain accompanied by symptoms such as morning stiffness, depression, fatigue, sleep disturbance, and impaired mental functioning [1]. According to current knowledge, hyperalgesia occurs due to hypersensitivity of central nociceptive pathways and deficient pain-inhibiting mechanisms [2]. Affective modulation of the processing of pain-related information has also been implicated in FMS pathology [3,4]. This is supported by neuroimaging studies showing more pronounced hyperactivity of brain areas mediating affective pain processing than of structures related to sensory pain [5–7]. It has been hypothesized that FMS patients are particularly vulnerable to the effects of negative mood, in the sense that pain potentiation during experiences of sadness, anxiety, or disgust may be stronger than in healthy individuals [8–10]. Further aberrances in emotion processing include impaired affect 1
Duschek et al. balance, difficulties in emotion recognition as well as increased emotional avoidance, catastrophizing, and alexithymia [11–15]. The present study is concerned with emotional influences on information processing in fibromyalgia. Attentional bias in terms of selective processing of negative information is believed to play an important role in psychopathology [16]. Enhanced attention toward threatening or general negative cues was reported for instance, in depression, anxiety disorders, posttraumatic stress, and personality disorders [17–21]. Selective attention to emotionally relevant stimuli interferes with information processing by capturing processing resources, thereby disrupting ongoing cognitive activity. This effect is most frequently studied using the Emotional Stroop Test. In this experimental paradigm, a subject is asked to name the colors of words with different emotional contents while ignoring the word meaning. Attentional bias is reflected by longer time to name the color of emotional as compared with neutral words of comparable frequency in everyday speech. A large number of studies have documented the fact that individuals with psychiatric disorders exhibit decelerated color naming of words with general negative connotations, or expressions specifically related to their diseases [16].
healthy control group, manifested in longer color naming times for negative with respect to neutral words. No group difference was expected for interference regarding the positive words. Due to the complex nature of fibromyalgia and its overlap with other disease entities, it seemed worthwhile in the present study to also investigate the contribution of specific features of FMS pathology to the expected attentional bias. For this purpose, psychiatric comorbidity was diagnosed, and clinical questionnaires on pain severity, depression, and anxiety were applied. We focused on depression and anxiety because of their high prevalence in FMS and also in consideration of reports on attentional bias in patients suffering from affective and anxiety disorders [18,20,21].
Methods Participants
In the field of chronic pain, the Emotional Stroop Test has mainly been used to investigate the hypothesis of hypervigilance to pain, i.e., unintentional attention toward pain-related information, which has been suggested to be relevant in the appearance of the disorder [22,23]. A recently published meta-analysis, which included 22 studies based on the Emotional Stroop Test, confirmed the occurrence of this effect but also alluded to its relatively small size and limited robustness [24]. To date, only a single study applied the Emotional Stroop Test in fibromyalgia research [25]. Here, patients and healthy subjects had to name the colors of words describing typical symptoms of FMS as well as disease-unrelated words with positive, negative, or neutral connotations. Patients showed significantly longer response times to the words from all categories, which was interpreted as indicative of general hypervigilance in FMS, i.e., a patients’ propensity to focus on task-irrelevant information.
Twenty-seven female FMS patients with a mean age of 52.7 years (SD = 9.2 years) participated in the study. They were recruited via interdisciplinary treatment programs for chronic pain patients, self-regulating communities, and the German Fibromyalgia Association. The patients were examined either by an anesthesiologist or specialist in pain medicine, and met the American College of Rheumatology criteria for FMS [28]. Exclusion criteria for participation comprised inflammatory causes of pain, neurological disorders, metabolic abnormalities, and severe somatic (e.g., cancer) or psychiatric (e.g., psychosis) diseases. Mean illness duration, i.e., the interval from first diagnosis of FMS, was 6.0 years (SD = 5.6 years). Tender point testing revealed an average of 15.3 active tender points (SD = 2.8). Sixteen (59.3%) patients were diagnosed with comorbid depression and four (14.8%) with comorbid anxiety disorders (panic disorder, generalized anxiety disorder, or phobias). At the time of assessment, eight (29.6%) patients were being treated with antidepressants, nine (33.3%) were using nonopioid analgesics, two (7.4%) opiates, and one (3.7%) anxiolytics. Mean time of education, which was taken as an estimate of educational background, was 13.7 years (SD = 3.1 years).
In the current study, a variant of the Emotional Stroop Test was applied in order to investigate the hypothesis of selective processing of affectively negative information in FMS. The presence of a negative attention bias seems plausible taking into account the aforementioned affective dysregulation such as disturbed affect balance and high levels of catastrophizing [11,12]. In addition, fibromyalgia exhibits high comorbidity with affective and anxiety disorders, and the patients display considerable elevations in self-report scales of depression and anxiety [8,26,27]. The Emotional Stroop Test included positive, negative, and neutral adjectives. In accordance with the reasoning presented above, we predicted greater selective attention toward negative cues in FMS patients with respect to a
The control group included 34 healthy women with a mean age of 53.9 years (SD = 8.4 years), who were recruited from local institutions for adult education and via personal contacts. Control subjects met the same exclusionary criteria as did the patients but were additionally required not to have any pain disorders. None of the control subjects were diagnosed with depression or anxiety disorders. None of them used antidepressants, analgesics, anxiolytics, or opiates. Mean time of education in the control group was 13.8 years (SD = 2.5 years). The patient and control groups did not differ significantly in terms of age (F [1,59] = 0.38, P = 0.56, partial eta squared
