The changing faces of somatization

Long COVID as a functional somatic symptom disorder caused by abnormally precise prior expectations during Bayesian perceptual processing: A new hypothesis and implications for pandemic response

This review proposes a model of Long-COVID where the constellation of symptoms are in fact genuinely experienced persistent physical symptoms that are usually functional in nature and therefore potentially reversible, that is, Long-COVID is a somatic symptom disorder. First, we describe what is currently known about Long-COVID in children and adults. Second, we examine reported "Long-Pandemic" effects that create a risk for similar somatic symptoms to develop in non-COVID-19 patients. Third, we describe what was known about somatization and somatic symptom disorder before the COVID-19 pandemic, and suggest that by analogy, Long-COVID may best be conceptualized as one of these disorders, with similar symptoms and predisposing, precipitating, and perpetuating factors. Fourth, we review the phenomenon of mass sociogenic (functional) illness, and the concept of nocebo effects, and suggest that by analogy, Long-COVID is compatible with these descriptions. Fifth, we describe the current theoretical model of the mechanism underlying functional disorders, the Bayesian predictive coding model for perception. This model accounts for moderators that can make symptom inferences functionally inaccurate and therefore can explain how to understand common predisposing, precipitating, and perpetuating factors. Finally, we discuss the implications of this framework for improved public health messaging during a pandemic, with recommendations for the management of Long-COVID symptoms in healthcare systems. We argue that the current public health approach has induced fear of Long-COVID in the population, including from constant messaging about disabling symptoms of Long-COVID and theorizing irreversible tissue damage as the cause of Long-COVID. This has created a self-fulfilling prophecy by inducing the very predisposing, precipitating, and perpetuating factors for the syndrome. Finally, we introduce the term "Pandemic-Response Syndrome" to describe what previously was labeled Long-COVID. This alternative perspective aims to stimulate research and serve as a lesson learned to avoid a repeat performance in the future.

Functional Gait Disorders: Clinical presentations, Phenotypes and Implications for treatment

BACKGROUND

Functional Gait Disorders (FGD) are a common presentation of motor-Functional Neurological Disorders (motor-FND) that affect walking ability.

AIM

To provide a narrative review of the current literature on FGD.

METHODS

A narrative overview of published literature was undertaken, based on a systematic search of relevant databases, authoritative texts and citation tracking.

RESULTS

FGD is multidimensional and disabling, with numerous phenotypes described in the literature, including 'knee buckling,' 'astasia-abasia' and 'excessive slowness.' Motor symptoms such as weakness or tremor, and non-motor symptoms, such as pain and fatigue may contribute to the disability and distress in FGD. Phenotypic features and clinical signs are seen in FGD that demonstrate inconsistency and incongruity with structural disease. A limited number of treatment studies have specifically focussed on FGD, however, reporting of outcomes from motor-FND cohorts has demonstrated short and long-term improvements in walking ability through multidisciplinary rehabilitation.

CONCLUSIONS

The relative contribution of motor and non-motor symptoms in FGD remains unknown, but it is likely that non-motor symptoms increase the illness burden and should be considered during assessment and treatment. Recommended treatment for FGD involves multidisciplinary rehabilitation, but optimum treatment elements are yet to be determined.

Association between COVID-19 symptoms, COVID-19 vaccine, and somatization among a sample of the Lebanese adults

Objectives

Long COVID syndrome, the poorly defined illness, has been increasingly mentioned in recent studies yet is still poorly understood especially when it comes to precipitating and modulating factors, the high prevalence of mental health problems associated with the COVID-19 pandemic has brought to light the hypothesis of the existence of a psychological component associated with the persistence of symptoms and if vaccination may serve as a modulating factor. This study aims to examine the prevalence of somatization disorders and association between persistent COVID-19 symptoms and COVID-19 vaccine with somatization among a sample of the Lebanese general population.

Methods

A cross-sectional study was carried out between September and October 2021. The snowball sampling technique was picked to choose a sample that addressed all Lebanese Mohafazat. Patient Health Questionnaire-15 (PHQ-15) was used to assess somatization.

Results

A total of 403 participants was enrolled in this study, with a mean age of 32.76 ± 13.24 years, 108 (26.8%) had medium somatization symptoms (PHQ-15 scores ≥10). Having persistent COVID symptoms (β=2.15) was significantly associated with more somatization, whereas the intake of COVID vaccine (β=-1.17) was significantly associated with less somatization.

Conclusion

Long lasting COVID-19 symptoms were closely related to somatization, although the administration of the COVID-19 vaccine was associated with less somatization. However, further studies are needed to provide a better understanding of the relationship between long COVID and somatization, on one hand, and the modulating factors on the other hand.

A review of functional neurological symptom disorder etiology and the integrated etiological summary model

Functional neurological symptom disorder (FNSD) is characterized by neurological symptoms that are unexplained by other traditional neurological or medical conditions. Both physicians and patients have limited understanding of FNSD, which is often explained as a physical manifestation of psychological distress. Recently, diagnostic criteria have shifted from requiring a preceding stressor to relying on positive symptoms. Given this shift, we have provided a review of the etiology of FNSD. Predisposing factors include trauma or psychiatric symptoms, somatic symptoms, illness exposure, symptom monitoring and neurobiological factors. Neurobiological research has indicated that patients with FNSD have a decreased sense of agency and abnormal attentional focus on the affected area, both of which are modulated by beliefs and expectations about illness. Sick role and secondary gain may reinforce and maintain FNSD. The integrated etiological summary model combines research from various fields and other recent etiological models to represent the current understanding of FNSD etiology. It discusses a potential causal mechanism and informs future research and treatment.

Neurasthenia, Spasmophilia and Chronic Fatigue Syndromes in France

This paper reviews French concepts of fatigue syn dromes, with a special emphasis on a reputedly unique ly French diagnosis: spasmophilia. Neurasthenia has virtually no place in contemporary French nosology of fatigue states, and chronic fatigue syndrome has not been accepted by all French researchers. The contro versies on neurasthenia and spasmophilia illustrate some of the social uses of diagnostic categories (e.g., legitimation of symptoms) and the ambivalence of physicians toward diagnostic labels based on clinical criteria.

Neurasthenia and Chronic Fatigue: Theory and Practice in Britain and America

The symptoms that make up the construct of neuras thenia, including fatigue and exhaustion, are dimension ally distributed in the community. The decision to create a category called neurasthenia is an arbitrary one, influenced by issues of severity and morbidity. The prevalence and nature of the resulting concept are also substantially influenced by the decision on how to classify the close relationships among excessive fatigue, depression and anxiety. Superimposed upon this classi fication is a second, parallel structure of illness beliefs. The original construct of neurasthenia as a physical disease that resulted from overwork, was of consider able utility to both doctors and patients. This early concept of neurasthenia can be recognized in the modem revival of interest in chronic fatigue syndrome (CFS) in Western cultures. The current highly charged atmosphere surrounding these diagnoses reflects the issues of legitimacy and non-legitimacy in illness, usually expressed in competing physical and psychologi cal explanations of ill health.

Resignation Syndrome: Catatonia? Culture-Bound?

Resignation syndrome (RS) designates a long-standing disorder predominately affecting psychologically traumatized children and adolescents in the midst of a strenuous and lengthy migration process. Typically a depressive onset is followed by gradual withdrawal progressing via stupor into a state that prompts tube feeding and is characterized by failure to respond even to painful stimuli. The patient is seemingly unconscious. Recovery ensues within months to years and is claimed to be dependent on the restoration of hope to the family. Descriptions of disorders resembling RS can be found in the literature and the condition is unlikely novel. Nevertheless, the magnitude and geographical distribution stand out. Several hundred cases have been reported exclusively in Sweden in the past decade prompting the Swedish National Board of Health and Welfare to recognize RS as a separate diagnostic entity. The currently prevailing stress hypothesis fails to account for the regional distribution and contributes little to treatment. Consequently, a re-evaluation of diagnostics and treatment is required. Psychogenic catatonia is proposed to supply the best fit with the clinical presentation. Treatment response, altered brain metabolism or preserved awareness would support this hypothesis. Epidemiological data suggests culture-bound beliefs and expectations to generate and direct symptom expression and we argue that culture-bound psychogenesis can accommodate the endemic distribution. Last, we review recent models of predictive coding indicating how expectation processes are crucially involved in the placebo and nocebo effect, delusions and conversion disorders. Building on this theoretical framework we propose a neurobiological model of RS in which the impact of overwhelming negative expectations are directly causative of the down-regulation of higher order and lower order behavioral systems in particularly vulnerable individuals.

Idiopathic environmental intolerance attributed to electromagnetic fields: a content analysis of British newspaper reports

Idiopathic environmental intolerance attributed to electromagnetic fields (IEI-EMF) is a controversial condition in which people describe symptoms following exposure to electromagnetic fields from everyday electrical devices. However, double-blind experiments have found no convincing evidence that electromagnetic fields cause these symptoms. In this study, we assessed whether recent newspaper reporting in the UK reflected this scientific evidence. We searched a database of newspaper articles to identify all those that contained IEI-EMF related keywords and selected a random sample of 60 for content analysis. For our primary outcomes, we assessed how many articles mainly or wholly presented an electromagnetic cause for IEI-EMF and how many discussed unproven treatments for the condition such as strategies intended to reduce exposure to electromagnetic fields or the use of complementary and alternative therapies. We also assessed whether the type of information source used by a newspaper article (e.g. scientist, person with IEI-EMF, politician) or the type of newspaper (broadsheet, tabloid, local or regional) was associated with either outcome. Of the 60 articles, 43 (71.7%) presented a mainly electromagnetic cause, compared to 13 (21.7%) which presented mainly non-electromagnetic causes and 4 (6.7%) which did not discuss a cause. 29 (48.3%) did not mention any potential treatment, while 24 (40.0%) mentioned eletromagnetic field related strategies and 12 (20.0%) mentioned complementary or alternative therapies. Articles which quoted someone with IEI-EMF were significantly more likely to report an electromagnetic cause and to present unproven treatments. Those which used a scientist as a source were more likely to present a non-electromagnetic cause for the condition. The widespread poor reporting we identified is disappointing and has the potential for to encourage more people to misattribute their symptoms to electromagnetic fields. Scientists should remain engaged with the media to counteract this effect.

Taking refuge from modernity: 21st century hermits

Idiopathic environmental intolerances, such as 'multiple chemical sensitivity' and 'electrosensitivity,' can drastically affect the quality of life of those affected. A proportion of severely affected patients remove themselves from modern society, to live in isolation away from the purported causal agent of their ill health. This is not a new phenomenon; reports of hermits extend back to the 3(rd) century AD. We conducted a literature review of case reports relating to ancient hermits and modern day reclusion resulting from idiopathic environmental intolerance, in order to explore whether there are similarities between these two groups and whether the symptoms of these 'illnesses of modernity' are simply a present-day way of reaching the end-point of reclusion. Whilst there were some differences between the cases, recurring themes in ancient and modern cases included: dissatisfaction with society, a compulsion to flee, reports of a constant struggle and a feeling of fighting against the establishment. The similarities which exist between the modern-day cases and the historical hermits may provide some insight into the extreme behaviours exhibited by this population. The desire to retreat from society in order to escape from harm has existed for many centuries, but in different guises.

A Bayesian account of 'hysteria'

This article provides a neurobiological account of symptoms that have been called ‘hysterical’, ‘psychogenic’ or ‘medically unexplained’, which we will call functional motor and sensory symptoms. We use a neurobiologically informed model of hierarchical Bayesian inference in the brain to explain functional motor and sensory symptoms in terms of perception and action arising from inference based on prior beliefs and sensory information. This explanation exploits the key balance between prior beliefs and sensory evidence that is mediated by (body focused) attention, symptom expectations, physical and emotional experiences and beliefs about illness. Crucially, this furnishes an explanation at three different levels: (i) underlying neuromodulatory (synaptic) mechanisms; (ii) cognitive and experiential processes (attention and attribution of agency); and (iii) formal computations that underlie perceptual inference (representation of uncertainty or precision). Our explanation involves primary and secondary failures of inference; the primary failure is the (autonomous) emergence of a percept or belief that is held with undue certainty (precision) following top-down attentional modulation of synaptic gain. This belief can constitute a sensory percept (or its absence) or induce movement (or its absence). The secondary failure of inference is when the ensuing percept (and any somatosensory consequences) is falsely inferred to be a symptom to explain why its content was not predicted by the source of attentional modulation. This account accommodates several fundamental observations about functional motor and sensory symptoms, including: (i) their induction and maintenance by attention; (ii) their modification by expectation, prior experience and cultural beliefs and (iii) their involuntary and symptomatic nature.

High symptom reporters are less interoceptively accurate in a symptom-related context

OBJECTIVE

We investigated the role of a symptom interpretation frame on the accuracy of interoception and on retrospective symptom reporting in nonclinical high and low reporters of medically unexplained symptoms.

METHODS

All participants (N=74) went through two subsequent trials of the Rebreathing Test, inducing altered respiration and other physical sensations as a result of a gradually increasing pCO(2) level in the blood. Each trial consisted of a baseline (60 s), a rebreathing phase (150 s), and a recovery phase (150 s). In one trial, the sensations were framed in a neutral way ("the gas mixture might alter breathing behavior and induce respiratory sensations"). In the other trial, a symptom frame was induced ("the gas mixture might alter breathing behavior and induce respiratory symptoms"). Breathing behavior was continuously monitored, subjective sensations were rated every 10 s, and after each trial, participants filled out a symptom checklist. Within-subject correlations between the subjective rating and its physiological referent were calculated for the rebreathing phase and recovery phase of each trial separately.

RESULTS

High symptom reporters had more (retrospective) complaints than low symptom reporters, especially in the symptom trial. Only in the symptom frame were high symptom reporters less accurate than low symptom reporters. The reduction in interoceptive accuracy (IA) in high symptom reporters was most striking in the recovery phase of the symptom frame trial.

CONCLUSION

A contextual cue, such as a reference to symptoms, reduced IA in high symptom reporters and this was more so during recovery from the symptom induction.

Chronic fatigue syndrome and related disorders in UK veterans of the Gulf War 1990-1991: results from a two-phase cohort study

BACKGROUND

The aim was to determine the prevalence of chronic fatigue syndrome (CFS), chronic fatigue and fibromyalgia in UK military personnel after the Gulf War 1990-1991.

METHOD

A two-phase cohort study was used. Three randomly selected subsamples identified from a population-based cross-sectional postal survey of over 10,000 current and ex-service UK military personnel (Gulf veterans were those deployed to the Gulf War 1990-1991; non-Gulf veterans were Bosnia peacekeepers 1992-1997 and those on active duty during the Gulf War 1990-1991 but not deployed) were recruited. Their disability status was assessed using the Short Form 36 physical functioning scale; Gulf veterans who reported physical disability (n=111) were compared with non-Gulf (n=133) veterans who reported similar levels of physical disability. Screening for known medical and psychiatric conditions was conducted to exclude medical explanations for disability and symptomatic distress. Standardised criteria for CFS, chronic fatigue and fibromyalgia were used.

RESULTS

Disabled Gulf veterans were more likely to be overweight, have elevated gamma-glutamyl transferase levels and screen positive for hypertension. There were no other clinically significant differences in clinical markers for medically explainable conditions. Disabled Gulf veterans were more likely than similarly disabled Bosnia and Era veterans (adjusted odds ratio 7.8, 95% confidence interval 2.5-24.5) to meet the criteria for CFS. Rates for other medically unexplained conditions were not significantly increased.

CONCLUSIONS

Symptoms in keeping with CFS account for a significant part of the symptomatic distress in Gulf veterans.

The association or otherwise of the functional somatic syndromes

OBJECTIVE

To review the evidence for overlap in the phenomenology of the Functional Somatic Syndromes (FSS). The FSS show considerable comorbidity, leading some to suggest they may be aspects of the same disorder.

METHODS

We conducted a selective review of peer-reviewed articles on the co-occurrence of FSS symptoms and diagnoses.

RESULTS

Considerable evidence of overlap was found at the level of symptoms, diagnostic criteria, and clinical diagnoses made.

CONCLUSIONS

Phenomenological commonalities support a close relationship between the FSS, although differences remain in other domains. Whether the FSS may best be considered the same or different will depend on the pragmatics of diagnosis.

Multisomatoform disorder: agreement between patient and physician report of criterion symptom explanation

OBJECTIVE

To determine the level of agreement between patients and expert physicians in whether criterion multisomatoform (MSD) symptoms are explained.

METHODS

We systematically collected reports from 280 primary care patients about whether they had suffered from any of 15 criterion MSD symptoms in the past month and whether they had received a medical explanation from a physician for positive criterion symptoms. The research team compared MSD symptom diagnoses derived from patient report with MSD symptom diagnoses derived from an expert physician report.

RESULTS

MSD symptom diagnoses derived from patient report had 98.7% sensitivity, 97.9% specificity, 89.3% positive predictive value, and 99.7% negative predictive value compared with MSD symptom diagnoses derived from an expert physician report. Analysis demonstrated that 15.0% of patients met symptom criteria for MSD, according to patient and physician report; 83.0% failed to meet symptom criteria for MSD, according to patient and physician report; 1.8% of patients met symptom criteria for MSD, according to patient report but not physician report, while 0.2% met symptom criteria for MSD according to physician report but not by patient report.

CONCLUSION

Patients demonstrated high agreement with a physician expert in somatization about whether criterion MSD symptoms are explained, suggesting revised screeners may accurately identify somatizing patients.

Multi-symptom illnesses, unexplained illness and Gulf War Syndrome

Explanatory models for the increased prevalence of ill health in Gulf veterans compared to those not deployed to the Gulf War 1990-1991 remain elusive. This article addresses whether multi-symptom reporting in Gulf veterans are types of medically unexplained symptoms and whether the alleged Gulf War Syndrome is best understood as a medically unexplained syndrome. A review of the epidemiological studies, overwhelmingly cross-sectional, describing ill health was conducted including those that used factor analysis to search for underlying or latent clinical constructs. The overwhelming evidence was that symptoms in Gulf veterans were either in keeping with currently defined psychiatric disorders such as depression and anxiety or were medically unexplained. The application of factor analysis methods had varied widely with a risk of over interpretation in some studies and limiting the validity of their findings. We concluded that ill health in Gulf veterans and the alleged Gulf War Syndrome is best understood within the medically unexplained symptoms and syndromes constructs. The cause of increased reporting in Gulf veterans are still not clear and requires further inquiry into the interaction between sociological factors and symptomatic distress.

Psychosocial responses to environmental incidents: a review and a proposed typology

OBJECTIVE

The objective of this review was to propose a typology for understanding the diversity of psychosocial reactions to environmental incidents.

METHODOLOGY

The first section provides an introduction and background to the topic; we then attempt to provide a typology of psychosocial responses to environmental incidents.

RESULTS

Response to an environmental incident can be usefully considered in terms of the exposure, the response of the individual, the action of professionals, the response of the community, and the influence of the society in which the incident occurs. We reviewed each of these factors.

CONCLUSIONS

By examining incidents in an ordered framework, we suggest that a more comprehensive understanding is possible. We also suggest some basic ways in which the psychosocial management of such difficult and diverse incidents could be improved.

Psychological mechanisms of medically unexplained symptoms: an integrative conceptual model

Theories of medically unexplained illness based on the concepts of dissociation, conversion, and somatization are summarized. Evidence cited in support of these theories is described and the conceptual strengths and shortcomings of each approach are considered. It is argued that each of these approaches adds to the understanding of unexplained illness but that none is able to provide a comprehensive explanation of the phenomenon. An integrative conceptual model of unexplained illness based on cognitive psychological principles is then presented. This model attempts to combine existing theoretical approaches within a single explanatory framework, extending previous theory by explaining how compelling symptoms can exist in the absence of organic pathology. The clinical and empirical implications of the model are then considered.

Are syndromes in environmental medicine variants of somatoform disorders?

To date, relatively little is known about the etiology, pathophysiology, diagnosis, therapy, prevention and prognosis of environment-related syndromes like multiple chemical sensitivity (MCS), idiopathic environmental intolerance (IEI), sick building syndrome (SBS), chronic fatigue syndrome (CFS), candida syndrome (CS) and burnout syndrome (BS). Part of the reason is that these syndromes have not been clearly defined and classified in scientific categories distinct from each other, and that they show clinical similarities to classified somatoform disorders. Furthermore, there are at least three possible explanations for the existence of these syndromes: (1) The syndromes may result from the interaction of environmental factors, individual susceptibility and psychological factors (i.e., how they are perceived and seen by the patient); (2) they may reflect socially and culturally accepted methods of expressing distress; and/or (3) they may be iatrogenic. Despite all the uncertainties in evaluation of environmental syndromes, physicians have the duty to take the affected person's problems seriously. A comprehensive systematic classification which better accounts for these complex clinical manifestations is long overdue. Until these syndromes are well defined, the terms used for them should definitely not be applied to connote a specific disease process.

Environmental sensitivity

The concept of environmental sensitivity is popular among a small group of physicians who believe that exposure to low levels of numerous environmental chemicals can cause a disease with numerous symptoms but no objective physical or laboratory abnormalities. The condition lacks a clear definition. Numerous theories that have been offered to explain the condition encompass immunotoxic, allergic, autoimmune, neurotoxic, cytotoxic, metabolic, behavioral, psychiatric, iatrogenic, and sociologic mechanisms. Environmental sensitivity has many features in common with other controversial syndromes, such as the chronic fatigue syndrome. Patients with environmental sensitivity frequently are subjected to unproven and unnecessary diagnostic tests and therapeutic modalities. In spite of the lack of physical illness and absence of pathology, patients often experience extreme disability, because their symptoms are triggered by common environmental exposures. The phenomenon of environmental sensitivity needs to be evaluated critically using scientifically sound methods. The practice of clinical ecology encompasses the practices of environmental sensitivity and its theories. Most methods of diagnosis and treatment have been disproved, and the concepts underlying these theories are not scientific. Alternative means of diagnosis and management are presented.

Idiopathic Environmental Intolerance

Toxicogenic and psychogenic theories have been proposed to explain idiopathic environmental intolerance (IEI). Part 2 of this article is an evidence-based causality analysis of the psychogenic theory using an extended version of Bradford Hill's criteria. The psychogenic theory meets all of the criteria directly or indirectly and is characterised by a progressive research programme including double-blind, placebo-controlled provocation challenge studies. We conclude that IEI is a belief characterised by an overvalued idea of toxic attribution of symptoms and disability, fulfilling criteria for a somatoform disorder and a functional somatic syndrome. A neurobiological diathesis similar to anxiety, specifically panic disorder, is a neurobiologically plausible mechanism to explain triggered reactions to ambient doses of environmental agents, real or perceived. In addition, there is a cognitively mediated fear response mechanism characterised by vigilance for perceived exposures and bodily sensations that are subsequently amplified in the process of learned sensitivity. Implications for the assessment and treatment of patients are presented.

Medically unexplained symptoms: an epidemiological study in seven specialities

OBJECTIVES

This study aimed to estimate the prevalence and risk factors for medically unexplained symptoms across a variety of specialities.

METHODS

A cross-sectional survey was conducted at two general hospitals in southeast London between 1995 and 1997. Eight hundred and ninety consecutive new patients from seven outpatient clinics were included. Demographic and clinical characteristic variables were assessed.

RESULTS

Five hundred eighty-two (65%) of the subjects surveyed returned completed questionnaires. A final diagnosis was available in 550 (62%). Two hundred twenty-eight (52%) fulfilled criteria for medically unexplained symptoms. The highest prevalence was in the gynecology clinic (66%). After adjustment for confounders, medically unexplained symptoms were associated with being female, younger, and currently employed. Psychiatric morbidity per se was not associated with the presence of medically unexplained symptoms, but was more likely in those complaining of multiple symptoms. Those with medically unexplained symptoms were less disabled, but more likely to use alternative treatment in comparison with those whose symptoms were medically explained. Patients with medically unexplained symptoms were more likely to attribute their illness to physical causes as opposed to lifestyle factors.

CONCLUSIONS

Medically unexplained symptoms are common across general/internal medicine and represent the most common diagnosis in some specialities. Medical behavior, training, and management need to take this into account.

Multiple chemical sensitivity: a review of the theoretical and research literature

Multiple chemical sensitivity (MCS) is a term used to describe a disorder characterized by a vast array of somatic, cognitive, and affective symptoms, the cause of which is attributed to exposure to extremely low levels of a variety of chemicals. Upon examination of the patient with a diagnosis of MCS, objective physical findings and consistent laboratory abnormalities are typically nonexistent. The concept of MCS has ignited considerable controversy in the fields of toxicology, immunology, allergy, psychology, and neuropsychology. Central to the controversy is the disagreement over the extent to which the manifestation of MCS is mediated by psychological factors. Because of the large number of neuropsychological symptoms associated with a diagnosis of MCS, neuropsychologists are increasingly receiving referrats for the assessment of these patients. It is important, therefore, that neuropsychologists become aware of the variety of clinical issues that must be taken into account when assessing an individual with a diagnosis of MCS. The theoretical and research literature on individuals with a diagnosis of MCS is reviewed here.

Functional somatic syndromes: one or many?

We review the concept and importance of functional somatic symptoms and syndromes such as irritable bowel syndrome and chronic fatigue syndrome. On the basis of a literature review, we conclude that a substantial overlap exists between the individual syndromes and that the similarities between them outweigh the differences. Similarities are apparent in case definition, reported symptoms, and in non-symptom association such as patients' sex, outlook, and response to treatment. We conclude that the existing definitions of these syndromes in terms of specific symptoms is of limited value; instead we believe a dimensional classification is likely to be more productive.

Psychological distress and rheumatic disease

Psychological factors influence the results of self-reports of pain, function and global severity in questionnaires such as the HAQ, SF-36 and the WOMAC. Persons with psychological distress use more resources, including medications, and have greater rates of work disability and joint surgery. Psychological status is influenced only very slightly by disease severity and tends to remain relatively constant over the course of the rheumatic disease. The psychological status of patients with differing rheumatic diseases is similar, and patients with rheumatoid arthritis do not have special psychological problems or psychological characteristics.

The time dimension in stress responses: relevance for survival and health

Within the Cognitive Activation Theory of Stress (CATS), the stress response occurs whenever there is a discrepancy between what the organism is expecting, and what really exists. It affects the biochemistry of the brain, mobilizes resources, affects performance, and endocrine, vegetative, and immune systems. Initial positive feedback and feed-forward mechanisms are gradually changed by homeostatic mechanisms. Slower reactive hormones such as cortisol seem to dampen the initial response. The time course may depend on psychological mechanisms. Subjects with efficient coping show the fast- and short-lasting catecholamine response, while subjects with high defense mechanisms (related to stimulus expectancies) may show more signs of prolonged activation. Non-coping individuals show a sustained general activation which may develop into somatic disease or illness.

Placebo response in environmental disease. Chelation therapy of patients with symptoms attributed to amalgam fillings

Treatment of patients who attribute their environmental illness to mercury from amalgam fillings is largely experimental. On the Symptom Check List, overall distress, and somatization, obsessive-compulsive, depression, and anxiety symptom dimensions, were increased in 50 consecutive patients examined, and Eysenck Personality Questionnaire scores suggested less extroversion and increased degree of emotional liability. Succimer (meso-2, 3-dimercaptosuccinic acid) was given at a daily dose of 30 mg/kg for five days in a double-blind, randomized placebo-controlled trial. Urinary excretion of mercury and lead was considerably increased in the patients who received the chelator. Immediately after the treatment and 5 to 6 weeks later, most distress dimensions had improved considerably, but there was no difference between the succimer and placebo groups. These findings suggest that some patients with environmental illness may substantially benefit from placebo.

Compensation neurosis: financial reward for illness as nocebo

Results of medical treatment are notoriously poor in patients with pending litigation after personal injury or disability claims, and for those covered by workers' compensation programs. Although some instances of overt malingering are documented by surveillance videos, most exaggerated illness behavior in compensation situations takes place because of a combination of suggestion, somatization, and rationalization. A distorted sense of justice, victim status, and entitlement may further the exaggerated sick role. Adversarial administrative and legal systems challenging the claimant to prove repeatedly he or she is permanently ill harden the conviction of illness and the individual's defense of the claim. Unfortunately, after advocating for one's injury before a sometimes doubting public for the several years required to resolve such claims, care eliciting behavior too often remains permanent. Because any improvement in the claimant's health condition may result in denial of disability status in the future, the claimant is compelled to guard against getting well and is left with no honorable way to recover from illness. Financial reward for illness thus functions as a powerful nocebo, a nonspecific force creating and exacerbating illness. Solutions require recognition that judging disability and work incapacity in others is an unscientific process and that adversarial systems rewarding permanent illness or injury, particularly self reported pain, are often permanently harmful. The remainder of the solution must be political.

Physical and mental problems attributed to dental amalgam fillings: a descriptive study of 99 self-referred patients compared with 272 controls

OBJECTIVE

The physical and mental symptomatology of 99 self-referred patients complaining of multiple somatic and mental symptoms attributed to dental amalgam fillings were compared with patients with known chronic medical disorders seen in alternative (N = 93) and ordinary (N = 99) medical family practices and patients with dental amalgam fillings (N = 80) seen in an ordinary dental practice.

METHOD

The assessments included written self-reports, a 131-item somatic symptom checklist; Eysenck Personality Questionnaire, the General Health Questionnaire, and Toronto Alexithymia Scale.

RESULTS

The dental amalgam sample reported significantly more physical symptoms from all body regions. Self-reports suggested that 62% suffered from a chronic anxiety disorder (generalized anxiety disorder or panic). Forty-seven percent suffered from a major depression compared with 14% in the two clinical-comparison samples and none in the dental control sample. Symptoms suggesting somatization disorder were found in 29% of the dental amalgam sample compared with only one subject in the 272 comparison subjects. One third of the dental amalgam patients reported symptoms of chronic fatigue syndrome compared with none in the dental control sample and only 2 and 6%, respectively, in the two clinical comparison samples. The dental amalgam group reported higher mean neuroticism and lower lie scores than the comparison groups.

CONCLUSION

Self-referred patients with health complaints attributed to dental amalgam are a heterogeneous group of patients who suffer multiple symptoms and frequently have mental disorders. There is a striking similarity with the multiple chemical sensitivity syndrome.

Chronic fatigue syndrome: a cognitive approach

Observations concerning the characteristics of patients who presented to a medical clinic with a principal complaint of chronic medically unexplained fatigue (Chronic Fatigue Syndrome or CFS) are described, including the cognitions (thoughts and assumptions) elicited from a sample of these patients who were treated using cognitive behavioural therapy. On the basis of these observations a cognitive theory of the aetiology of CFS is proposed. These observations have implications for the treatment of patients with CFS.

Psychiatry in the allergy clinic: the nature and management of patients with non-allergic symptoms

Patients with multiple unexplained somatic symptoms attributed to allergy frequently present to physicians and often the physician fails to find evidence for allergic or immunological mechanisms underlying the presenting symptoms. This article discusses the social and cultural background to this disorder. We then consider current explanatory models for symptoms and finally, we consider appropriate management, starting with the initial consultation, the identification of psychiatric disorders when present, and concluding with suggestions for subsequent treatment and guidance on appropriate referral.

The environmental somatization syndrome

Patients with environmental somatization syndrome (ESS) believe that their symptoms are caused by exposure to tangible components of the external environment or by ergonomic stress at work. ESS is distinguishable by mental contagiousness and by the patients' focus on the external environment as cause of the illness. The presentation is often polysymptomatic, and epidemic outbreaks may appear. The patients usually refuse alternative explanations of their symptoms and discredit and reject any suggestion of a psychogenic etiology. It is important to distinguish between hygienic problems and ESS problems, particularly when poor and inadequate hygienic factors are present simultaneously with an ESS epidemic.

Seasonal affective disorder, environmental hypersensitivity and somatisation

An association between seasonal affective disorder (SAD) diagnosed according to DSM-III-R criteria and 'environmental hypersensitivity', candida hypersensitivity, and food allergies is reported in two patients. It is suggested that patients with somatisation disorder may present with symptoms of SAD and other media-popularised diagnoses in a form reminiscent of the cases of multiple media-popularised diagnoses.