Somatization: a psychoneuroimmune perspective

Explaining medically unexplained symptoms-models and mechanisms

We summarize the psychological mechanisms that have been linked to the development and maintenance of medically unexplained symptoms (MUS). Many models postulate that patients with MUS misinterpret physical sensations and show other cognitive abnormalities (e.g., an over-exclusive concept of health) that play a major role in symptom development. While there is strong evidence for the role of cognitive aspects, there is less evidence for their interaction with perceptual features (e.g., perceptual sensitivity, lowered perceptual threshold). Modern neuroimaging techniques show that the expectation of symptoms leads to the activation of brain areas corresponding to symptom perception, while distraction from symptoms reduces brain activity in perception areas. The frequently postulated monocausal organic attribution for physical sensations by patients with MUS needs to be modified, as many patients report multiple symptom attributions, including psychological. Symptom attributions and causal models depend on memorized concepts, and so memory processes need to be investigated in more detail. Aberrations in memory processes not only offer a link to understanding perceptual processes, but are also involved in doctor-patient interaction. This encounter is characterized by unsuccessful medical reassurance, which again involves memory processes. We conclude that psychological mechanisms such as expectation, distraction, and memory processes need to be integrated with biological models to aid understanding of MUS.

Medically unexplained symptoms and between-group differences in 24-h ambulatory recording of stress physiology

People with medically unexplained symptoms (MUS) often have a comorbid history of stress and negative affect. Although the verbal-cognitive and (peripheral) physiological stress systems have shown a great degree of independence, at the same time it is claimed that chronic stress and negative affect can result in a disregulated physiological stress system, which may lead to MUS. Previous studies could not demonstrate a straightforward between subject relationship between MUS and stress physiology, supporting the view of independence. The aim of the current study was to further explore this relationship using an improved methodology based on ecologically valid 24-h real-life ambulatory recordings. Seventy-four participants (19 male; 55 female) with heterogeneous MUS were compared with 71 healthy controls (26 male; 45 females). Momentary experienced somatic complaints and mood, heart rate, cardiac autonomic activity, respiration and saliva cortisol were monitored using electronic diary and ambulatory registration devices. Participants with MUS reported much more momentary complaints and negative affect as compared to controls. Although MUS seemed to be associated with elevated heart rate and reduced low and very-low frequency heart period variability, these effects disappeared after controlling for differences in sports behaviour. No group differences were found for cardiac autonomic activity, respiration, end-tidal CO(2) and saliva cortisol. Our 24-h real-life ambulatory study did not support the existence of a connection between MUS and disregulated peripheral stress physiology. Future studies may instead focus on central measures to reveal potential abnormalities such as deviant central processing of visceral signals in MUS patients.

The cognitive behavioural model of medically unexplained symptoms: A theoretical and empirical review

The article is a narrative review of the theoretical standing and empirical evidence for the cognitive behavioural model of medically unexplained symptoms (MUS) in general and for chronic fatigue syndrome (CFS) and irritable bowel syndrome (IBS) in particular. A literature search of Medline and Psychinfo from 1966 to the present day was conducted using MUS and related terms as search terms. All relevant articles were reviewed. The search was then limited in stages, by cognitive behavioural therapy (CBT), condition, treatment and type of trial. Evidence was found for genetic, neurological, psychophysiological, immunological, personality, attentional, attributional, affective, behavioural, social and inter-personal factors in the onset and maintenance of MUS. The evidence for the contribution of individual factors, and their autopoietic interaction in MUS (as hypothesised by the cognitive behavioural model) is examined. The evidence from the treatment trials of cognitive behavioural therapy for MUS, CFS and IBS is reviewed as an experimental test of the cognitive behavioural models. We conclude that a broadly conceptualized cognitive behavioural model of MUS suggests a novel and plausible mechanism of symptom generation and has heuristic value. We offer suggestions for further research.

Adaptogenic potential of a polyherbal natural health product: report on a longitudinal clinical trial

Stress is a risk factor for a number of diseases and is an important predictor of health in general. Herbal medicines have been used as adaptogens to regulate and improve the stress response and there is evidence to support the use of herbal medicines for this purpose. We conducted an open-label longitudinal study on the natural health product, OCTA(c), a compound mixture of eight herbs, to determine its effects on perceptions of stress. Eighteen participants were enrolled in the study and were followed over a period of 3 months. Primary endpoints included scores from four validated questionnaires (SF-36v2, PSS, STAI and BDI-II), serum DHEA, ALT, AST and creatinine all measured at 12 weeks. Seventeen patients completed the study. Except for the physical summary score of the SF36 questionnaire, all the subjective scores indicated a highly significant (P < 0.0001) improvement in the participants' ability to cope with stress. No adverse effects were reported and there was no evidence of damage to the liver or kidney based on serum markers. Initial evidence for this polyherbal compound supports its potential as an effective 'adaptogenic' aid in dealing with stress. Further research using a randomized controlled design is necessary to confirm the findings from this pilot study.

Conflict, collusion or collaboration in consultations about medically unexplained symptoms: the need for a curriculum of medical explanation

OBJECTIVE

To identify the basis of the communication problems that characterise consultations about medically unexplained symptoms (MUS) and to identify implications for clinical education.

METHOD

Recent research into the details of clinical communication about MUS was reviewed narratively and critically, and broader research literature was scrutinised from the perspective of a practitioner who wishes to provide patients with explanations for such symptoms.

RESULTS

Consultations about MUS often involve contest between patients' authority, resting on their knowledge of their symptoms, and practitioners' authority, based on the normal findings of tests and investigations. The outcome of consultations can therefore depend on the strategies that each party uses to press their authority, rather than on clinical need.

CONCLUSION

Contest is a product of patients and practitioners occupying separate conceptual 'ground'. Avoiding contest requires the practitioner to find common conceptual ground within which each party can understand and discuss the symptoms. Finding common ground by collusion with explanations that patients suggest can damage clinical relationships. Instead the practitioner needs to fashion explanation that is acceptable to both parties from available medical and lay material.

PRACTICE IMPLICATIONS

Although practitioners commonly fashion such explanations, this aspect of their professional role seems not to be greatly valued amongst practitioners or in medical curricula. Clinical education programmes could include curricula in symptom explanation, drawing from research in medicine, psychology and anthropology.

Trauma and medically unexplained symptoms towards an integration of cognitive and neuro-biological accounts

Medically unexplained symptoms (MUS) are frequently associated with a history of traumatization. The first purpose of the present review paper was to investigate systematically the evidence for such relation in a subset of clinical samples with MUS presenting with functional somatization: chronic pelvic pain, irritable bowel syndrome and conversion and somatization disorder. The second purpose was to critically review three dominant models explaining the relation between trauma and MUS (i.e. dissociation, conversion and hierarchical cognitive models). The latter model in particular adequately accounts for the non-volitional and non-intentional character of MUS and explains how traumata can affect the development of MUS without assuming that previous trauma is a necessary prerequisite of MUS. The cognitive model, however, lacks integration with current neurobiological findings, indicative of central stress-and central nervous system alterations in MUS. The final purpose of the present paper was, therefore, to review current neurobiological studies focused on trauma and MUS and to formulate a research agenda to integrate these neurobiological developments with cognitive models for MUS.

Somatization disorder, a cause of difficult pain: a case report

Presented is a case report of a 55-year-old man with a suspected diagnosis of pancreatic malignancy who was referred for pain management to the pain and palliative care clinic. A diagnosis of pain originating from a malignancy was later ruled out. The patient was referred for psychiatric evaluation, where his pain symptoms were confirmed to be somatoform in origin. This case highlights the importance of ruling out somatization as the cause of symptoms in difficult pain patients.

Tumor associated release of interleukin-10 alters the prolactin receptor and down-regulates prolactin responsiveness of immature cortical thymocytes

The soluble factors produced either by Ehrlich's ascites carcinoma (EAC) or thymic adherent cells (TAC) of tumor-bearing mice comprising of CD11b(+) and CD11c(+) antigen-presenting cells caused a sharp decrease in prolactin (PRL)-induced ConA-mediated effect on survival of PNA(+) thymocytes. Similar suppression of PRL-induced effect was observed when the cells were cocultured with TAC of EAC-bearing mice. Anti-IL-10 antibody could reverse the PRL inability to induce ConA-mediated effect on PNA(+) thymocyte survival, indicating the presence of IL-10 in EAC culture supernatant (EAC sup) and thymic microenvironment. IL-10 could block PRL-induced proliferation of PNA(+) thymocytes without affecting spontaneous apoptosis. IL-10 altered the expression of the long-form (LF) of PRL-R and reduced the PRL binding of the cells, suggesting down-regulation of the PRL effect on PNA(+) thymocyte by the cytokine. Induction of tumor, which was found to increase the IL-10 secretion by TAC, also modified the PRL-R (LF) to PRL-R (SF). Since PRL plays a role in survival, proliferation and differentiation of lymphoid progenitor cells, the tuning of PRL action by IL-10 may be a possible mechanism of depletion of immature cortical thymocytes and thymic atrophy in tumor-bearing mice.

Depression in cancer patients: a critical review

Cancer patients experience several stressors and emotional upheavals. Fear of death, interruption of life plans, changes in body image and self-esteem, changes in social role and lifestyle are all important issues to be faced. Moreover, Depressive Disorders may impact the course of the disease and compliance. The cost and prevalence, the impairment caused, and the diagnostic and therapeutic uncertainty surrounding depressive symptoms among cancer patients make these conditions a priority for research. In this article we discuss recent data, focusing on detection of Depressive Disorders, biological correlates, treatments and unmet needs of depressed cancer patients.

Alexithymia and interleukin variations in somatoform disorder

OBJECTIVE

The aim of the present study was to investigate if somatoform disorders (SFD) are associated with changes in the normal serum levels of important interleukins, and further, to establish if these changes are related to the presence and severity of alexithymia in patients with SFD.

METHODS

Twenty-four unmedicated patients who met the International Classification of Diseases (ICD-10) diagnostic criteria for SFD completed the psychological questionnaire to assess alexithymia (Toronto Alexithymia Scale), symptom reporting (SCL-90-R) and diagnostic criteria for SFD (Screening for Somatoform Symptoms scale). Serum concentrations of soluble interleukin 2 receptor alpha (sIL-2 Ralpha), IL-4, IL-6, IL-10 and IL-12 were determined in patients with SFD and in 9 healthy subjects.

RESULTS

In patients with SFD, serum levels of IL-6 (p < 0.001), IL-10 (p = 0.047) and immunoglobulin E (p = 0.045) were significantly increased in comparison with healthy controls. Additionally, a negative correlation was observed between the level of alexithymia ('total' Toronto Alexithymia Scale score) and the serum levels of sIL-2 Ralpha (r = -0.538) in SFD.

CONCLUSIONS

Taken together, these results suggest that SFD, with clinically significant alexithymia, are associated with a reduction in Th1-mediated immune function and an increase in the activation of the Th2 immune function, indicated by the augmented serum levels of IL-6 and IL-10 and elevated immunoglobulin E.

There are no association between IgE levels and symptoms of anxiety and depression in the adult female general population. The Hordaland Health Study (HUSK)

There are multiple reports of increased prevalence of anxiety and depression in patients with asthma, eczema and rhinitis. Suggested biological mechanisms underlying these associations most commonly involve IgE. However, the association between anxiety/depression and IgE has hardly been studied, and the aim of the present study will therefore be to examine the hypothesized association between anxiety/depression and IgE in a general adult female population. A sub-sample of 374 female participants in a population-based general health study in Norway (the Hordaland Health Study) with participation rate 70% was screened for total and allergen-specific IgE. Anxiety and depression were measured employing the Hospital Anxiety and Depression Scale (HADS). This design ensured adequate statistical power, and the population-approach ensured satisfactory variance in both IgE and anxiety/depression. No association between case level or symptom load of anxiety/depression and total or allergen-specific IgE was found. Non-significant tendencies were both positive and negative. This finding was robust across continuous and categorical statistical approaches. Our finding does not question the commonly reported associations between anxiety/depression and asthma, rhinitis and eczema. We do, however, question the relevance of IgE as an aetiological factor in the biological chain underlying these associations.

[Psychological stress, immune function and disease development. The psychoneuroimmunologic perspective]

Interdisciplinary psychoneuroimmunological (PNI) research increasingly demonstrates clinically relevant interrelations between psychological stressors and the onset or progression of chronic diseases. Disturbances of the bi-directional interaction between the nervous system, the immune system and the endocrine system have been hypothesized to be implicated in several diseases. Here, we review evidence from psychoneuroimmunology within the theoretical framework of allostatic load to conceptualize some of these associations. Interdisciplinary PNI research investigating the importance of psychological stress for the higher incidence of infections, decreased responses to vaccinations and delayed wound healing is reviewed. Furthermore, the literature supporting similar associations with regard to progression of oncological diseases and autoimmune disorders is reviewed with a focus on breast cancer and multiple sclerosis. The accumulating evidence regarding the importance of neuroendocrine-immune interaction in these diseases may thus lead to novel insights into pathogenetic mechanisms and could contribute to the development of novel preventive and therapeutic strategies.

An empirical delineation of the heterogeneity of chronic unexplained fatigue in women

OBJECTIVES

To test the hypothesis that medically unexplained chronic fatigue and chronic fatigue syndrome (CFS) are heterogeneous conditions, and to define the different conditions using both symptom and laboratory data.

METHODS

We studied 159 women from KS, USA. A total of 51 of these suffered from fatigue consistent with established criteria for CFS, 55 had chronic fatigue of insufficient symptoms/severity for a CFS diagnosis and 53 were healthy controls matched by age and body mass index (BMI) against those with CFS. We used principal components analyses to define factors that best described the variable space and to reduce the number of variables. The 38 most explanatory variables were then used in latent class analyses to define discrete subject groups.

RESULTS

Principal components analyses defined six discrete factors that explained 40% of the variance. Latent class analyses provided several interpretable solutions with four, five and six classes. The four-class solution was statistically most convincing, but the six-class solution was more interpretable. Class 1 defined 41 (26%) subjects with obesity and relative sleep hypnoea. Class 2 were 38 (24%) healthy subjects. Class 3 captured 24 (15%) obese relatively hypnoeic subjects, but with low heart rate variability and cortisol. Class 4 were 23 (14%) sleep-disturbed and myalgic subjects without obesity or significant depression. The two remaining classes with 22 (14%) and 11 (7%) subjects consisted of the most symptomatic and depressed, but without obesity or hypnoea. Class 5 had normal sleep indices. Class 6 was characterized by disturbed sleep, with low sleep heart rate variability, cortisol, and sex hormones.

CONCLUSION

Chronic medically unexplained fatigue is heterogeneous. The putative syndromes were differentiated by obesity, sleep hypnoea, depression, physiological stress response, sleep disturbance, interoception and menopausal status. If these syndromes are externally validated and replicated, they may prove useful in determining the causes, pathophysiology and treatments of CFS.

The potentially somatizing effect of clinical consultation

Many patients who present physical symptoms that their doctors cannot explain by physical disease have persisting symptoms and impairment. An influential view has been that such symptoms are the somatization of emotional distress, but there has also been concern that medical practice contributes to shaping these presentations. Analysis of patients' accounts indicate that they approach these consultations with a sense of being the expert on the nature and reality of their symptoms and, in primary care at least, they seek convincing explanations, engagement, and support. They often describe doctors as doubting that their symptoms are real and as not taking their symptoms seriously. Observational research has demonstrated that patients presenting idiopathic symptoms in primary care generally provide cues to their need for explanation or to psychosocial difficulties. Their doctors tend to provide simple reassurance rather than detailed explanations, and often disregard psychosocial cues. Patients seem to intensify their presentation in consequence, elaborating and extending their accounts of their symptoms, perhaps in the effort to engage their doctors and demonstrate the reality of their symptoms. When doctors propose physical investigation and treatment in response to such escalating presentation, they thereby inadvertently somatize patients' psychological presentation. Consultations, therefore, have elements of contest, whereby patients seek engagement from doctors who seek to disengage. Although provision of a medical label, such as a functional diagnosis, can legitimize patients' complaints and avoid contest, this is at the risk of indicating that medicine can take responsibility for managing the symptoms. More collaborative relationships rely on doctors recognizing patients' authority in knowing about their symptoms, and providing tangible explanations that make sense to the patient and allow them to tolerate or manage the symptoms. Researchers need to study how doctors can best achieve these aims within routine consultations.

Abnormal illness behaviour: physiological, psychological and social dimensions of coping with distress

PURPOSE OF REVIEW

Pilowsky introduced the term 'abnormal illness behaviour' to characterize syndromes of excessive or inadequate response to symptoms, including hypochondriasis, somatization, and denial of illness. This review summarizes recent work from sociology, health psychology and psychiatry that contributes to an understanding of the processes that may underlie abnormal illness behaviour.

RECENT FINDINGS

Disturbances in the regulation of physiological systems may account for many 'unexplained' symptoms and sickness behaviour. Increased attention to bodily sensations, sensitivity to pain and catastrophizing play important roles in illness behaviour in medical illness. Developmental adversities and parental modelling of illness behaviour in childhood may increase bodily preoccupation and health care utilization. Apparent cross-national differences in illness behaviour may reflect differences in health care systems, but cultural models of illness and social stigma remain important determinants of illness denial and avoidance of mental health services.

SUMMARY

Research into illness behaviour is relevant to efforts to rethink the psychiatric nosology of somatoform disorders. The discrete somatoform disorders might well be replaced by a dimensional framework that identifies specific pathological processes in cognition, perception and social behaviour that contribute to bodily distress, impaired coping, inappropriate use of health services, chronicity and disability.