Biological sensitisation and psychological amplification: gateways to subjective health complaints and somatoform disorders

Sensory Thresholds and Peripheral Nerve Responses in Chronic Tension-Type Headache and Neuropsychological Correlation

Chronic tension-type headache (CTTH) is a common disease with no fully defined pathophysiological processes. We designed a study to value electrophysiological responses in these patients and their correlation with possible psychopathological manifestations in order to deepen understanding of central and peripheral mechanisms of CTTH. In 40 patients with CTTH and 40 healthy controls, we used electrical stimulation to determine sensory threshold (SPT) and pain perception threshold (PPT) and the characteristics of the electrophysiological sensory nerve action potential (SNAP): initial sensory response (ISR) and supramaximal response (SMR). We then calculated the intensity differences between thresholds (IDT), namely SPT-PPT, ISR-SMR and SMR-PPT, and correlated these IDTs with psychological characteristics: trait and state anxiety, depression, and emotional regulation. The SPT, together with the ISR and SMR thresholds, were higher (p < 0.01) in CTTH patients. The SMR-PPT IDT was smaller and correlated with significantly higher indicators of depression, state and trait anxiety, and poorer cognitive reappraisal. CTTH patients have less capacity to recognize non-nociceptive sensory stimuli, greater tendency toward pain facilitation, and a poor central pain control requiring higher stimulation intensity thresholds to reach the start and the peak amplitude of the SNAP. This is consistent with relative hypoexcitability of the Aβ nerve fibers in distant regions from the site of pain, and therefore, it could be considered a generalized dysfunction with a focal expression. Pain facilitation is directly associated with psychological comorbidity.

Exposure to Potentially Traumatic Events, Posttraumatic Stress Symptoms, Pain Catastrophizing, and Functional Somatic Symptoms Among Individuals With Varied Somatic Symptoms: A Moderated Mediation Model

The relationships between exposure to potentially traumatic events (PTEs), as well as posttraumatic stress symptoms (PTSS) and somatic syndromes, have recently been exemplified. Exposure to PTEs can also set in motion complex psychological processes such as pain catastrophizing that is associated with PTSS and somatic syndromes. However, the specific moderating role of pain catastrophizing in these links remains relatively unexamined. The present study aims to assess a moderated mediation model in which catastrophizing will moderate the indirect effect of exposure to PTEs on the number of somatic symptoms and chronic pain severity via PTSS, among individuals with somatic syndromes. A volunteers' sample of 175 Israeli adults with varied somatic symptoms responded to online validated self-report questionnaires in a cross-sectional designed study. Participants' self-reported PTSS rates (57.1%) were high. PTSS and pain catastrophizing, but not exposure to PTEs, were related to chronic pain severity. Interestingly, a moderated mediation analysis indicated that the indirect effect of catastrophizing in the relation between exposure to PTEs and the number of somatic symptoms via PTSS existed only among those with high levels of catastrophizing. The present study highlights the assumption that functional somatic syndromes (FSS) have much in common. Our findings support a moderated mediation model that begins with exposure to PTEs that leads to PTSS, which in turn increase the number of somatic symptoms. Higher levels of pain catastrophizing might attenuate this indirect link by affecting the interpretation of PTSS and create a vulnerability to more somatic symptoms. Thus, changes in cognitive-sensory processing in the form of catastrophic thinking can affect psychobiological processes and heighten sensitivity to stimuli arising in the body and should be considered as possible target for future research and psychological interventions.

Associations Between Posttraumatic Stress Symptoms, Anxiety Sensitivity, Socially Prescribed Perfectionism, and Severity of Somatic Symptoms Among Individuals with Fibromyalgia

OBJECTIVES

The contribution of psychological risk factors to the intensification of pain experienced among individuals with fibromyalgia syndrome (FMS) is relatively under-studied. The present study aims to explore associations between FMS-related somatic symptom severity and two personality tendencies: anxiety sensitivity (AS) and socially prescribed perfectionism (SPP). Furthermore, the relative contributions of these personality tendencies are examined vis-à-vis the experience of potentially traumatic events (PTEs) and the psychopathology of posttraumatic stress symptoms (PTSS).

METHODS

A volunteer sample of 117 Israeli adults with FMS responded to online validated self-report questionnaires regarding their PTEs, PTSS, somatic symptom severity, FMS, AS, and SPP in a cross-sectional study.

RESULTS

Participants' self-reported PTSS rates (61.5%) were high. AS and SPP were positively related to somatic symptom severity. Interestingly, we found that PTSS positively predicted the severity of somatic symptoms above and beyond the contributions of AS and SPP.

CONCLUSIONS

The present study supports the assumption that psychological risk factors may affect the expression of somatic symptoms and the interpretation of pain stimulus arising in the body that might eventually be experienced as excessively painful. The study also suggests that above and beyond psychological risk factors, PTSS may express a high predominance and affect pain perception among participants with FMS.

The Four-Cluster Spectrum of Mind-Body Interrelationships: An Integrative Model

Despite the shift toward a biopsychosocial paradigm of medicine, many physicians and mental health professionals (MHPs) find it difficult to treat patients with psycho-somatic disorders. This situation is particularly troublesome due to the high prevalence of these conditions. Although progress has been made over the last few decades in understanding mechanisms underlying the mind-body relationship, disparities remain between research and its clinical implementation. One possible reason for this is the lack of a comprehensive, agreed-upon model that incorporates a biopsychosocial framework and is rooted in an understanding of the various psychobiological pathways. Such a model would enable better communication between physicians and MHPs, allowing them to provide coordinated, stratified treatment. In this paper, four archetypal case studies, together with standard care options are presented to illustrate the current state of affairs. A four-tiered conceptual model of mind-body interrelationships based on pathophysiological and psychopathological mechanisms is suggested to help optimize the treatment of somatic complaints. This Four-Cluster model consists of: (1) Organic Conditions: Structural, or degenerative processes that can affect mood and psychological responses but are not clearly exacerbated by stress. (2) Stress Exacerbated Diseases: Biological disorders with a distinct pathophysiology, such as inflammatory or autoimmune diseases, whose progression is clearly exacerbated by stress. (3) Functional Somatic Syndromes: Conditions wherein heightened sensitivity to stimuli together with hyper-reactivity of the autonomic system form a "vicious cycle" of mutually enhancing learning processes. These processes involve biological mechanisms, such as central sensitization and psychological mechanisms such as catastrophization and selective attention. (4) Conversion Disorder: Physical manifestations of psychological distress, expressed somatically. Symptoms are solely an expression of problems in patients' psychic functioning and are not caused by biological pathology. Finally, suggested management of the aforementioned case studies is presented through the lens of the Four-Cluster model and a proposed integration of our model with existing theories is discussed. As it is rooted in an understanding of psychobiological pathways of illness, the proposed model enables a new way to discern which form of mind-body interaction is manifesting in different diseases and proposes a way to coordinate treatment plans accordingly, to enhance the accuracy and efficacy of care.

Psychological distress, neuroticism and disability associated with secondary chronic headache in the general population - the Akershus study of chronic headache

Background

Primary headaches are associated with psychological distress, neuroticism and disability. However, little is known about headache-related disability and psychological distress among people with secondary chronic headaches.

Methods

30,000 persons aged 30–44 from the general population was screened for headache by a questionnaire. The responder rate was 71%. The International Classification of Headache Disorders with supplementary definitions for chronic rhinosinusitis and cervicogenic headache were used. The Hopkins Symptom Checklist-25 assessed high psychological distress, the Migraine Disability Assessment questionnaire assessed disability, and Eysenck Personality Questionnaire assessed neuroticism.

Results

Ninety-five of the 113 eligible participants (84%) completed the self-reported questionnaire. A total of 38 people had chronic post-traumatic headache, 21 had cervicogenic headache, and 39 had headache attributed to chronic rhinosinusitis, while 9 had co-occurrence of chronic post-traumatic and cervicogenic headache. Six persons had miscellaneous secondary chronic headaches. Overall, 49% of those with secondary chronic headache reported high psychological distress, which is significantly higher than in the general population. A high level of neuroticism was significantly more common in those with secondary chronic headache than in the general population. Severe headache-related disability was reported by 69%. 92 persons were followed up after 3 years. A low headache frequency was the only significant predictor of improvement of ≥ 25% in headache days. Having post-traumatic or cervicogenic headache and not headache attributed to chronic rhinosinusitis predicted an increased risk &gt; 25% worsening of headache days or having a severe disability at 3 years follow-up.

Conclusion

Psychological distress and neuroticism were more common among people with secondary chronic headache than in the general population. Only a high headache frequency was significantly associated with increased headache disability at baseline and a poor prognosis in the long term.

Fatigue symptoms in relation to neuroticism, anxiety-depression, and musculoskeletal pain. A longitudinal twin study

BACKGROUND

The nature of the relationship between fatigue and its risk factors is poorly understood. In the present study the genetic and environmental association between anxiety-depression, musculoskeletal (MS) pain and fatigue was examined, and the role of neuroticism as a shared risk factor that may possibly explain the co-occurrence between these phenotypes was investigated in a combined cross-sectional and longitudinal twin design.

METHODS

The sample consisted of 746 monozygotic (MZ) and 770 dizygotic (DZ) twins in the age group of 50-65 (mean = 57.11 years, SD = 4.5). Continuous measures of fatigue symptoms and the other phenotypes were employed. Using Cholesky modeling, genetic and environmental influences on the phenotypes, and the associations among them, were determined. Analyses were performed using measures of neuroticism obtained concurrently and 13-19 years earlier.

RESULTS

Results from multiple regression analyses showed that neuroticism, anxiety-depression symptoms, and MS pain were all significantly associated with fatigue, controlling for sex, education, and general health indices. The best-fitting biometric models included additive genetic and individual-specific environmental effects. Heritabilities in the 0.40-0.53 range were demonstrated. Furthermore, while there was a considerable overlap in genetic risk factors between the four phenotypes, a substantial proportion of the genetic risk shared between anxiety-depression and fatigue, and between MS pain and fatigue, was independent of neuroticism.

CONCLUSION

Evidence for a common underlying susceptibility to report fatigue symptoms, genetically linked to neuroticism, anxiety-depression, and MS pain, was found. Both unique and pleiotropic effects appear to be involved in the genetic architecture of the phenotypes.

Musculoskeletal pain in Primary Care Physiotherapy: Associations with demographic and general health characteristics

BACKGROUND

Many patients reporting musculoskeletal pain present to Primary Care Physiotherapy with costly comorbid overlapping complaints that remain medically unexplained. These subjective health complaints (SHC) incorporate coexisting multi-site musculoskeletal pain and varied non-musculoskeletal complaints (e.g. anxiety, tiredness). The role of these non-musculoskeletal complaints is acknowledged in spinal musculoskeletal disorders, but less so for peripheral musculoskeletal disorders.

OBJECTIVE

This cross-sectional study explored the relationships between self-reported musculoskeletal pain sites, non-musculoskeletal complaints and disability among people reporting spinal or peripheral musculoskeletal pain.

METHODS

Fifty individuals with spinal musculoskeletal pain and fifty with peripheral musculoskeletal pain provided data on disability, number of musculoskeletal pain sites and non-musculoskeletal complaints. Relationships between these variables were examined for each group using Pearson's correlation coefficient and linear regression analysis.

RESULTS

Participants with spinal musculoskeletal pain recorded significantly more pain sites and non-musculoskeletal complaints than participants with peripheral musculoskeletal pain. However, there was no significant difference in disability between the groups. Non-musculoskeletal complaints were significantly associated with disability (correlation = 0.41, p < 0.01) and number of pain sites (correlation = 0.42, p < 0.01). Number of pain sites and disability were not significantly associated in either group. Participants with spinal musculoskeletal pain reported more tiredness, dizziness, anxiety and sleep problems. Participants reporting dizziness, anxiety, sadness/depression and sleep problems had higher disability.

CONCLUSION

Further studies must confirm the robustness of these associations, to permit comparisons between clinical and general populations and aid identification of causal factors. Considering SHC within individualised management programmes may improve outcomes.

Brain sensitization to external and internal stimuli

Sensitization is defined as a non-associative learning process occurring when repeated administrations of a stimulus result in a progressive amplification of a response (Shettleworth, 2010). The purpose of this review paper is to discuss whether brain sensitization is helpful in common health problems in man. The paper reviews data on brain sensitization covering increased behavioral, physiological, cognitive, and emotional responses in man and animals. The paper concludes that brain sensitization may be a helpful concept to understand subjective and "unexplained" health complaints (nonspecific muscle pain, mood changes, fatigue, and gastrointestinal complaints), and, therefore, relevant for evidence based treatment and prevention of these common health problems.

Psychosocial predictors of irritable bowel syndrome diagnosis and symptom severity

OBJECTIVE

This study explored the role of psychosocial factors in predicting both membership to either an irritable bowel syndrome (IBS) or control group, and the severity of IBS symptoms.

METHODS

A total of 149 participants (82 IBS and 67 controls) completed a battery of self-report inventories assessing disposition and environment, cognitive processes, and psychological distress. Logistic regression analyses were used to assess predictive contribution of psychosocial variables to IBS diagnosis. Hierarchical linear regression was then used to assess the relationship of psychosocial variables with the severity of IBS symptoms.

RESULTS

Significant predictors of IBS were found to be alexithymia, the defectiveness/shame schema, and four coping dimensions (active coping, instrumental support, self-blame, and positive reframing), χ(2) (6, N=130)=46.99, p<.001, with predictive accuracy of 72%. Significant predictors of IBS symptom severity were two of the alexithymia subscales (difficulty identifying feelings, and difficulty describing feelings), gender, the schemas of defectiveness/shame and entitlement, and global psychological distress. This model predicted IBS severity F (6, 64)=16.94, p<.001 and accounted for 61.3% of the variability in IBS severity scores.

CONCLUSION

Psychosocial variables account for a large percentage of the differences between an IBS and control group, as well as the variance of symptoms experienced within the IBS group. Alexithymia and the defectiveness schema appear to be related to both IBS and symptom severity.

Personality traits and psychological distress in persons with chronic tension-type headache. The Akershus study of chronic headache

OBJECTIVES

To explore the relationship between chronic tension-type headache (CTTH) and psychological factors (personality traits and psychological distress) in a population-based sample and to determine the influence of headache frequency and medication days.

METHODS

An age- and sex-stratified random sample of 30,000 persons aged 30-44 years from the general population received a mailed questionnaire. Those with a self-reported chronic headache were interviewed by neurological residents. The questionnaire response rate was 71%, and the rate of participation in the interview was 74%. The International Classification of Headache Disorders was used. Personality traits were assessed by the Eysenck Personality Questionnaire (EPQ), neuroticism and lie scale, and level of psychological distress, by the Hopkins Symptom Checklist-25 (HSCL-25). For comparison, cross-sectional data from the Danish and the Norwegian general population using the same instruments were used.

RESULTS

Persons with CTTH had a significantly higher neuroticism score and a significantly higher level of psychological distress than the general population. Headache- or medication days per month had no significant influence on the neuroticism- and lie scores or the HSCL-25 score.

CONCLUSIONS

Persons with CTTH have a high level of neuroticism and psychological distress. This can be either a primary or a secondary effect related to the premorbid psyche or caused by the chronic pain and is a question that future studies should address.

Analgesic effects of ethanol are influenced by family history of alcoholism and neuroticism

BACKGROUND

Although personality factors and family history of substance abuse influence how individuals experience pain and respond to analgesics, the combined effects of those factors have not been extensively studied. The objective of this study was to consider the possible role of personality trait of neuroticism and family history of alcoholism on the experience of pain and their role in the analgesic response to an ethanol challenge.

METHODS

Forty-eight healthy subjects participated in this study; thirty-one had a positive family history of alcoholism (FHP), seventeen had a negative family history of alcoholism (FHN). They were also categorized based on their neuroticism (N) scores (low N = 28, and high N = 20). This was a double-blind, placebo-controlled, randomized, within-subject design study of intravenous administration of three doses of ethanol. The testing consisted of 3 separate test days scheduled at least 3 days apart. Test days included a placebo day (saline solution), low-exposure ethanol day (targeted breathalyzer = 0.040 g/dl), and high-exposure ethanol day (targeted breathalyzer = 0.100 g/dl). Noxious electrical stimulation and pain assessments were performed prior to start of infusion and at the 60-minute infusion mark.

RESULTS

The analgesic effect of ethanol was mediated by an interaction between the personality trait of neuroticism and family history. Individuals with family history of alcoholism and high N scores reported significantly more analgesia on low dose of ethanol than those with low N scores. There was no difference in the analgesic response to ethanol among FHNs with low and high N scores.

CONCLUSION

These findings support the conclusion that neuroticism and family history of alcoholism both influence the analgesic response of alcohol. Individuals with high N scores and FHP have the strongest response to ethanol analgesia particularly on the low exposure to alcohol.

Reading sensations: understanding the process of distinguishing 'fine' from 'sick'

Sensations form the bases of our recognition that we are well, or, alternatively, that something is wrong. What is the process which transforms a sensation into a symptom? In this article, I draw on fieldwork from Lombok, Indonesia to propose a model of the processes through which sensations become symptoms. Perceptional and interpretive decisions regarding what sensations need to be attended to as potential symptoms may be the result of personal awareness of cultural ideas about vulnerability, sensation duration, and interference with activities. The interpretation of sensations is always tentative, conditional on further cultural information regarding whether the sensation should be constructed into a symptom. I conclude by suggesting a model of the processes through which sensations are interpreted, become pathologized, and are socially legitimated.

Health Complaints and Satisfied With the Job? A Cross-Sectional Study on Work Environment, Job Satisfaction, and Subjective Health Complaints

OBJECTIVE

The aim of this study was to examine the prevalence of subjective health complaints (SHCs) among satisfied and dissatisfied workers. The second aim was to evaluate whether any SHC differences were attributable directly to the work environment or mediated by the individual perception of the environment (satisfactory or not).

METHOD

In a cross-sectional study of 458 employees (56% women) in 5 different organizations, work environment, job satisfaction, and SHC were measured.

RESULTS

Satisfied workers reported an average of five to six subjective health complaints that correspond to the prevalence found in a Norwegian general population. Work environment explained 43% of the variance for job satisfaction and 9% of the variance in SHCs.

CONCLUSION

SHCs are common among satisfied workers. Work environment has only a limited influence on this validated health indicator.

Myalgic encephalomyelitis: a review with emphasis on key findings in biomedical research

This review examines research findings in patients with myalgic encephalomyelitis in light of the current debate about this chronic multiple-symptom, multiorgan, multisystem illness and the conflicting views in medicine. These issues cannot be separated from the political opinions and assertions that conflict with science and medicine, and will be part of this review as they have enormous consequences for scientific and medical research, patients, clinicians, carers and policy makers.

Physical ill health and risk of psychosis

Patients with psychosis have been found to suffer from physical illnesses more commonly than the general population. In this report, self-reported physical ill health and its correlates among subjects with and without vulnerability to psychosis in a sample of first-degree relatives, help-seekers and controls were investigated. Perceived physical health was statistically significantly poorer among subjects with minor symptoms on the Structured Interview for Prodromal Symptoms and those vulnerable to psychosis than among those without symptoms measured by 13 somatoform symptom sum scores of the Symptom Checklist-90. Those at current risk of psychosis had a significantly higher mean sum score on the 13 somatic items (mean=21.1) than others (mean=9.6). Having physical symptoms or a self-reported physician-diagnosed illness was significantly associated with vulnerability to psychosis (odds ratio=3.05). The subjects with a mood disorder (odds ratio=4.33) had significantly more commonly physician-diagnosed illnesses than those who had no diagnosis or any other diagnosis. Physical ill health seems to be common among those vulnerable to psychosis.

Subjective health complaints are more prevalent in Maasais than in Norwegians

The aim of this observational, population-based study was to compare subjective health complaints (SHC) in Norwegians, living in a Western welfare society, and Maasai people, living in rural Kenya under primitive conditions. An interview-based version of SHC inventory was used. Data from 320 Maasais were compared to data from 1243 Norwegians. The Maasais had significantly higher score than the Norwegians on 23 of 28 items, involving musculoskeletal, "pseudo-neurological" and gastrointestinal complaints. The Maasais, living under primitive conditions, close to nature, seems to have more SHC than Norwegians, living in a modern, highly developed and industrialized country.