Somatosensory amplification as a possible source of subjective symptoms behind modern health worries

Associations between symptoms, modern health worries, and somatosensory amplification in patients with building-related symptoms

OBJECTIVE

The objective of the present study was to investigate the associations between somatosensory amplification, modern health worries (MHWs), and symptoms among patients with building-related symptoms (BRS).

METHODS

Patients with self-reported and medically confirmed BRS (n = 83) were included in this cross-sectional study. The Somatosensory Amplification Scale (SSAS) was used to quantify the tendency to amplify somatic sensations and perceive them as unpleasant and dangerous. Concerns about harmful effects of modern technologies were assessed with the Modern Health Worries Scale (MHWS). Symptoms commonly found in different forms of environmental intolerance were assessed with the Environmental Hypersensitivity Symptom Inventory (EHSI).

RESULTS

Patients with BRS were characterized by more frequent and more severe environmental hypersensitivity symptoms compared to a reference population. Females and those with co-morbid self-reported chemical intolerance reported even more symptoms. MHWS and SSAS scores showed weak to moderate associations with symptoms, even after adjusting for socio-economic variables. However, neither the mean MHWS score or the SSAS score of our sample differed from normative scores.

CONCLUSION

Patients with BRS are not characterized by elevated levels of MHWs and somatosensory amplification, thus other, psychosocial and/or environmental, factors may have contributed to the development of the condition. However, the associations between severity of symptoms and MHWs and somatosensory amplification suggest that psychosocial characteristics may substantially influence symptom experience in this group.

Modern health worries and annoyance from environmental factors are largely unrelated to smoking, alcohol consumption, and physical activity

OBJECTIVE

Modern health worries, as well as environmental annoyance from chemical agents, noise, and electromagnetic exposure are associated with symptom reporting and marked affective-behavioural changes. As promotion and protection of health is a primary characteristic of these conditions, it can be expected that they will be related to less risk behaviour (smoking and alcohol consumption) and more health behaviour (physical activity), both cross-sectionally and longitudinally.

METHODS

Hypotheses were tested in a sample of 2336 individuals participating in T1 and T2 data collection (3 years apart) of the Västerbotten Environmental Health Study, Sweden. Health-related behaviours were assessed using single self-report questions. Smoking was measured on a binary (yes-or-no) scale; frequency of alcohol consumption and physical activity was measured on a 5-point and a 4-point scale, respectively.

RESULTS

Modern health worries showed no cross-sectional association with the three behaviours, whereas annoyance was typically inversely, very weakly, related to smoking and alcohol consumption. Physical activity was significantly positively associated only with chemical annoyance. None of the variables significantly predicted change of behaviours at T2 after controlling for the respective T1 value and demographic variables.

CONCLUSIONS

Individuals with high levels of modern health worries and annoyance from various environmental agents are not clearly characterized by a healthier lifestyle. Perhaps they focus on the alleviation of their existing symptoms; alternatively, somatic symptom distress decreases their cognitive-affective resources necessary for a long-term life style change.

An idiographic approach to idiopathic environmental intolerance attributed to electromagnetic fields (IEI-EMF) part I. Environmental, psychosocial and clinical assessment of three individuals with severe IEI-EMF

IEI-EMF refers to an environmental illness whose primary feature is the occurrence of symptoms that are attributed to exposure to weak electromagnetic fields (EMFs). There is a growing evidence that this condition is characterized by marked individual differences thus a within-subject approach might add important information beyond the widely used nomothetic method. A mixed qualitative/quantitative idiographic protocol with a threefold diagnostic approach was tested with the participation of three individuals with severe IEI-EMF. In this qualitative paper, the environmental, psychosocial, and clinical aspects are presented and discussed (results of ecological momentary assessment are discussed in Part II of this study). For two participants, psychopathological factors appeared to be strongly related to the condition. Psychological assessment indicated a severe pre-psychotic state with paranoid tendencies, supplemented with a strong attentional focus on bodily sensations and health status. The psychological profile of the third individual showed no obvious pathology. Overall, the findings suggest that the condition might have uniformly been triggered by serious psychosocial stress for all participants. Substantial aetiological differences among participants with severe IEI-EMF were revealed. The substantial heterogeneity in the psychological and psychopathological profiles associated with IEI-EMF warrants the use of idiographic multimodal assessments in order to better understand the different ways of aetiology and to facilitate person-taylored treatments.

The interplay of self-critical rumination and resting heart rate variability on subjective well-being and somatic symptom distress: A prospective study

OBJECTIVE

The aim of this prospective study was to investigate the association of self-critical rumination, autonomic function (indexed by a time domain metric of resting heart rate variability-RMSSD), subjective well-being and somatic symptom distress.

METHOD

84 healthy participants (73 females; mean age = 23.56, SD = 3.35 years) completed the Somatic Symptom Severity Scale of the Patient Health Questionnaire and Mental Health Continuum Short Form at two timepoints (at baseline and six months later). Resting heart rate variability (HRV) was assessed at baseline, along with content specific rumination using the Self-Critical Rumination Scale. Four moderation analyses were performed to test these associations.

RESULTS

The interaction between resting HRV and self-critical rumination significantly explained somatic symptom distress at baseline. For those participants who had high resting HRV, somatic symptom distress was basically independent from the level of self-critical rumination. At the same time, lower resting HRV was associated with higher somatic symptom distress, especially in the presence of more ruminative thoughts. Prospectively, however, the interaction between rumination and resting HRV was not a significant predictor of somatic symptom distress. The association between resting HRV and self-critical rumination did not explain the variance on subjective well-being, but subjective well-being was negatively related to self-critical rumination.

CONCLUSION

Our findings potentially indicate that self-critical rumination could have a long-term negative impact on psychological functioning, even in a non-clinical sample, and highlight that a lower level of parasympathetic activation, assessed with RMSSD, might be an important factor in the relationship of self-critical rumination and somatic symptom distress.

Modern health worries and idiopathic environmental intolerance attributed to electromagnetic fields are associated with paranoid ideation

OBJECTIVE

Paranoid ideation is assumed to characterize worries about possible harmful effects of modern technologies (MHWs) and idiopathic environmental intolerances (IEIs), such as IEI attributed to electromagnetic fields (IEI-EMF). Empirical evidence on these associations is scarce.

METHODS

In a cross-sectional on-line survey, participants of a community sample (n = 700; mean age: 28.4 ± 12.0; 434 females) completed the Somatosensory Amplification Scale, the Modern Health Worries Scale, and the Paranoid Ideation scale of the Symptom Checklist 90 Revised. They were considered IEI-EMF if (1) they categorized themselves so, (2) they had experienced symptoms that they attributed to the exposure to electromagnetic fields, and (3) the condition impacted their everyday functioning.

RESULTS

Paranoid ideation was significantly positively associated with MHWs (standardized β = 0.150, p < .001) even after controlling for socio-demographic variables and somatosensory amplification tendency, an indicator of somatic symptom distress. Also, paranoid ideation explained significant variability in IEI-EMF (OR = 1.090, 95% CI: 1.006-1.180, p = .035) even after statistically controlling for socio-demographic variables and somatosensory amplification.

CONCLUSIONS

Paranoid ideation was found to be associated with MHWs and IEI-EMF. This association appears independent of general somatic symptom distress in both cases. This might partly explain the temporal stability of these constructs.

Association between somatic symptoms and modern health worries

OBJECTIVE

Modern health worries (MHWs) refer to perceived risk to personal health from technological changes and features of modern life, and is associated with health outcomes. The present objective was to test the hypotheses of (i) associations between MHWs and a global measure of typical somatization symptoms, referred to as somatic symptom distress, and (ii) associations between MHWs and a broad range of specific typical somatization symptoms and eye/skin and airway symptoms.

METHODS

Cross-sectional population-based data were used. Validated instruments were used to assess MHWs (Modern Health Worries Scale), typical somatization symptoms (Patient Health Questionnaire 15-item Somatic Symptom Severity Scale, PHQ-15), eye/skin and airway symptoms (Environmental Hypersensitivity Symptom Inventory), depression and anxiety (Hospital Anxiety and Depression Scale). Multivariate linear regression analyses were conducted with MHWs as dependent variable, symptoms as independent variables, and background variables, anxiety and depression as confounding variables.

RESULTS

When controlled for background variables, MHWs were statistically significantly, but only very weakly, associated with global PHQ-15 score, most of the specific typical somatization symptoms, and eye/skin and airway symptoms. When controlled also for depression and anxiety, the associations were statistically significant, but even more weakly associated with global PHQ-15 score and most of the specific symptoms.

CONCLUSIONS

The results suggest a very small increased risk of somatic symptom distress and related specific symptoms in MHW, and that depression and anxiety are confounding variables in these associations.

Modern health worries: A systematic review

OBJECTIVE

Modern health worries (MHWs) refer to people's concerns about possible harmful effects of modern technologies, and are widespread in the developed countries. The aim of the present work was to provide comprehensive, yet integrated understanding for MHWs and associated factors.

METHODS

Following the PRISMA guideline, a systematic review was conducted based on 48 empirical articles published between 2001 and 2018 (Prospero registration number: CRD42018103756). All empirical studies were included that (1) were published between 2001 and 2018 in peer-reviewed scientific journals in English, German, or Hungarian, (2) used the Modern Health Worries Scale or any of its sub-scales, and (3) assessed associations between MHWs and other constructs and/or compared criterion groups (i.e. purely psychometric studies were excluded).

RESULTS

The results from the review suggest that female gender, age, somatic symptom distress and idiopathic environmental intolerances, holistic thinking, and paranoid beliefs are positively associated with MHWs, whereas educational qualification and the five major dimensions of personality appear not to be.

CONCLUSION

Scientific inquiry on the MHWs phenomenon is still in its descriptive-explorative phase; more rigorously designed studies are needed. The presented theoretical framework integrates illness-related and holistic thinking-related aspects of MHWs as a starting point to guide further research in this area.

Modern health worries: Deriving two measurement invariant short scales for cross-cultural research with Ant Colony Optimization

Worries about possible harmful effects of new technologies (modern health worries) have intensely been investigated in the last decade. However, the comparability of translated self-report measures across countries is often problematic. This study aimed to overcome this problem by developing psychometrically sound brief versions of the widely used 25-item Modern Health Worries Scale (MHWS) suitable for multi-country use. Based on data of overall 5,176 individuals from four European countries (England, Germany, Hungary, Sweden), Ant Colony Optimization was used to identify the indicators that optimize model fit and measurement invariance across countries. Two scales were developed. A short (12-item) version of the MHWS that represents the four-factor structure of the original version and an ultra-short (4-item) scale that only measures the general construct. Both scales show that overall levels of health worries were highest in England and Hungary, but that the main reason for concern (e.g. electromagnetic radiation or food related fears) differs considerably between these countries. This study also shows that even if measurement invariance of translated self-report instruments across countries is problematic, it can be optimized by using adequate item selection procedures. Differences of modern health worries across countries and recommendations for cross-cultural research are discussed.

Modeled and perceived RF-EMF, noise and air pollution and symptoms in a population cohort. Is perception key in predicting symptoms?

BACKGROUND

Psychosocial research has shown that perceived exposure can influence symptom reporting, regardless of actual exposure. The impact of this phenomenon on the interpretation of results from epidemiological research on environmental determinants of symptoms is unclear.

OBJECTIVE

Our aim was to compare associations between modeled exposures, the perceived level of these exposures and reported symptoms (non-specific symptoms, sleep disturbances, and respiratory symptoms) for three different environmental exposures (radiofrequency electromagnetic fields (RF-EMF), noise, and air pollution). These environmental exposures vary in the degree to which they can be sensorially observed.

METHODS

Participant characteristics, perceived exposures, and self-reported health were assessed with a baseline (n = 14,829, 2011/2012) and follow-up (n = 7905, 2015) questionnaire in the Dutch population-based Occupational and Environmental Health Cohort (AMIGO). Environmental exposures were estimated at the home address using spatial models. Cross-sectional and longitudinal regression models were used to examine the associations between modeled and perceived exposures, and reported symptoms.

RESULTS

The extent to which exposure sources could be observed by participants likely influenced correlations between modeled and perceived exposure as correlations were moderate for air pollution (r_Sp = 0.34) and noise (r_Sp = 0.40), but less so for RF-EMF (r_Sp = 0.11). Perceived exposures were consistently associated with increased symptom scores (respiratory, sleep, non-specific). Modeled exposures, except RF-EMF, were associated with increased symptom scores, but these associations disappeared or strongly diminished when accounted for perceived exposure in the analyses.

DISCUSSION

Perceived exposure has an important role in symptom reporting. When environmental determinants of symptoms are studied without acknowledging the potential role of both modeled and perceived exposures, there is a risk of bias in health risk assessment. However, the etiological role of exposure perceptions in relation to symptom reporting requires further research.

Longitudinal associations between risk appraisal of base stations for mobile phones, radio or television and non-specific symptoms

INTRODUCTION

Studies found that higher risk appraisal of radiofrequency electromagnetic fields is associated with reporting more non-specific symptoms such as headache and back pain. There is limited data available on the longitudinal nature of such associations and what aspects of risk appraisal and characteristics of subjects are relevant.

OBJECTIVE

To examine cross-sectional and longitudinal associations between risk appraisal measures and non-specific symptoms, and assess the role of subject characteristics (sex, age, education, trait negative affect) in a general population cohort.

METHODS

This study was nested in the Dutch general population AMIGO cohort that was established in 2011/2012, when participants were 31-65 years old. We studied a sample of participants (n = 1720) who filled in two follow-up questionnaires in 2013 and 2014, including questions about perceived exposure, perceived risk, and health concerns as indicators of risk appraisal of base stations, and non-specific symptoms.

RESULTS

Perceived exposure, perceived risk, and health concerns, respectively, were associated with higher symptom scores in cross-sectional and longitudinal analyses. Only health concerns (not perceived exposure and perceived risk) temporally preceded high symptom scores and vice versa. Female sex, younger age, higher education, and higher trait negative affect were associated with higher risk appraisal of mobile phone base stations.

DISCUSSION

The findings in this study strengthen the evidence base for cross-sectional and longitudinal associations between higher risk appraisal and non-specific symptoms in the general population. However, the directionality of potential causal relations in non-sensitive general population samples should be examined further in future studies, providing information to the benefit of risk communication strategies.

How do illness-anxious individuals process health-threatening information? A systematic review of evidence for the cognitive-behavioral model

According to the cognitive-behavioral model, illness anxiety is developed and maintained through biased processing of health-threatening information and maladaptive responses to such information.

OBJECTIVE

This study is a systematic review of research that attempted to validate central tenets of the cognitive-behavioral model regarding etiological and maintenance mechanisms in illness anxiety.

METHODS

Sixty-two studies, including correlational and experimental designs, were identified through a systematic search of databases and were evaluated for their quality.

RESULTS

Outcomes were synthesized following a qualitative thematic approach under categories of theoretically driven mechanisms derived from the cognitive-behavioral model: attention, memory and interpretation biases, perceived awareness and inaccuracy in perception of somatic sensations, negativity bias, emotion dysregulation, and behavioral avoidance.

CONCLUSIONS

Findings partly support the cognitive-behavioral model, but several of its hypothetical mechanisms only receive weak support due to the scarcity of relevant studies. Directions for future research are suggested based on identified gaps in the existing literature.

Eveningness is associated with poor sleep quality and negative affect in obsessive-compulsive disorder

Background Obsessive-compulsive disorder (OCD) is characterized by intrusive thoughts and repetitive behaviors that severely encumber daily functioning. OCD patients seem to exhibit sleep disturbances, especially delayed bedtimes that reflect disrupted circadian rhythmicity. Morningness-eveningness is a fundamental factor reflecting individual variations in diurnal preferences related to sleep and waking activities. Eveningness reflecting a delayed sleep-wake timing has repeatedly been associated with sleep problems and negative affect (NA). Therefore, the aim of this study was to examine the associations between morningness-eveningness, sleep complaints, and symptom severity in OCD patients and compared with a mixed psychiatric control group. Materials and methods The data of 49 OCD and 49 mixed psychiatric inpatients (with unipolar depression and anxiety disorders) were analyzed. Patients completed questionnaires regarding morningness-eveningness, sleep quality, nightmare frequency, depression, anxiety, and affective states. Obsessive and compulsive symptom severity was also assessed within the OCD group by clinician-rated scales. Results Eveningness preference was associated with impaired sleep quality and higher NA in OCD patients. In addition, impaired sleep quality showed a moderate correlation with anxiety and strong correlations with depressive symptoms and NA. Interestingly, in the mixed psychiatric group, eveningness was not linked to NA, and sleep quality also showed weaker associations with depressive symptoms and NA. Within the OCD group, eveningness preference was predictive of poorer sleep quality regardless the influence of depressive symptoms. Conclusion Our findings suggest that eveningness and sleep complaints are predictive of affective dysfunctions, and should be carefully considered in the evaluation and treatment of OCD patients.

Somatosensory amplification - An old construct from a new perspective

The paper reviews and summarizes the history and the development of somatosensory amplification, a construct that plays a substantial role in symptom reports. Although the association with negative affect has been supported by empirical findings, another key elements of the original concept (i.e. body hypervigilance and the tendency of focusing on mild body sensations) have never been appropriately addressed. Recent findings indicate that somatosensory amplification is connected with phenomena that do not necessarily include symptoms (e.g. modern health worries, or expectations of symptoms and medication side effects), and also with the perception of external threats. In conclusion, somatosensory amplification appears to refer to the intensification of perceived external and internal threats to the integrity of the body ("somatic threat amplification") rather than amplification of perceived or actual bodily events only. Practical implications of this new approach are also discussed.

Are modern health worries associated with medical conspiracy theories?

This study was concerned with whether Medical Conspiracy Theories (MCTs), along with other variables (demographics, ideology and health perceptions) are associated with Modern Health Worries (MHWs). MCTs were significantly associated with MHWs over and above all other variables. Older individuals, with more religious and right-wing beliefs had higher MHWs. In addition, those who used Complementary and Alternative Medicine (CAM) and individuals who perceived their mental health as worse than their peers were also more likely to display higher MHWs. Implications for helping health professions understand their patients' health-related beliefs and choices were discussed.

Modeled and Perceived Exposure to Radiofrequency Electromagnetic Fields From Mobile-Phone Base Stations and the Development of Symptoms Over Time in a General Population Cohort

We assessed associations between modeled and perceived exposure to radiofrequency electromagnetic fields (RF-EMF) from mobile-phone base stations and the development of nonspecific symptoms and sleep disturbances over time. A population-based Dutch cohort study, the Occupational and Environmental Health Cohort Study (AMIGO) (n = 14,829; ages 31-65 years), was established in 2011/2012 (T0), with follow-up of a subgroup (n = 3,992 invited) in 2013 (T1; n = 2,228) and 2014 (T2; n = 1,740). We modeled far-field RF-EMF exposure from mobile-phone base stations at the home addresses of the participants using a 3-dimensional geospatial model (NISMap). Perceived exposure (0 = not at all; 6 = very much), nonspecific symptoms, and sleep disturbances were assessed by questionnaire. We performed cross-sectional and longitudinal analyses, including fixed-effects regression. We found small correlations between modeled and perceived exposure in AMIGO participants at baseline (n = 14,309; rSpearman = 0.10). For 222 follow-up participants, modeled exposure increased substantially (>0.030 mW/m2) between T0 and T1. This increase in modeled exposure was associated with an increase in perceived exposure during the same time period. In contrast to modeled RF-EMF exposure from mobile-phone base stations, perceived exposure was associated with higher symptom reporting scores in both cross-sectional and longitudinal analyses, as well as with sleep disturbances in cross-sectional analyses.

Nature relatedness is connected with modern health worries and electromagnetic hypersensitivity

Although nature relatedness is considered a positive characteristic, its relationship to constructs involving worries about the negative effects of artificial environmental factors is also feasible. A questionnaire assessing modern health worries, electrosensitivity, somatosensory amplification, spirituality, and nature relatedness was completed by 510 individuals. Nature relatedness was related to electrosensitivity, modern health worries, and spirituality. In a binary logistic regression analysis, somatosensory amplification, modern health worries, and nature relatedness were associated with electrosensitivity, and nature relatedness moderated the connection between modern health worries and electrosensitivity. In naive representations, “natural” might be associated with health, whereas “modern” and “artificial” evoke negative associations.

Attribution-Based Nocebo Effects. Perceived Effects of a Placebo Pill and a Sham Magnetic Field on Cognitive Performance and Somatic Symptoms

BACKGROUND

Negative non-specific (nocebo-like) effects of medications and electromagnetic fields are often described as results of mistaken attribution.

PURPOSE

The current study aimed to find empirical evidence supporting this theory.

METHOD

Participants completed questionnaires assessing modern health worries, health anxiety, and somatosensory amplification, were assigned to one of three conditions (placebo pill with sedative information, sham magnetic field, or control), and completed a 14-min vigilance task. Changes in physiological arousal (heart rate, heart rate variability, and skin conductance) and reported symptoms were also measured. Finally, causal attributions concerning cognitive performance and reported symptoms were assessed.

RESULTS

No increase in symptom reports and physiological arousal was measured in the two intervention groups. A perceived negative effect on cognitive performance was attributed to both sham conditions, and attributions were connected to modern health worries. A proportion of reported symptoms was ascribed to the placebo pill but not to the sham magnetic field. Symptom attributions were not related to any assessed psychological variables.

CONCLUSIONS

An aroused physiological state is not necessary for the automatic causal attribution process. Negative effects attributed to medication and environmental factors can be regarded as unavoidable side effects of human cognitive-emotional functioning; they might be alleviated, but cannot be completely eradicated.

The many faces of somatosensory amplification: The relative contribution of body awareness, symptom labeling, and anxiety

The questionnaire study aimed to evaluate the relative contribution of body awareness, subjective symptoms, and anxiety to the construct of somatosensory amplification in both healthy controls (n = 475) and patients visiting their general practitioner (n = 236). Regression analysis explained 52.0 percent of total variance of the somatosensory amplification scale scores. Body awareness was the most influential predictor (β = 0.489, p < 0.001) when considering all predictors simultaneously. The results suggest that dispositional interoceptive focus, as indicated by body awareness, may be an important aspect of somatosensory amplification, over and above dispositional anxiety or subjective symptom report.

Somatic symptoms and holistic thinking as major dimensions behind modern health worries

BACKGROUND

Modern health worries (MHWs) were related to somatic symptoms and to preference of holistic healing methods in previous studies.

PURPOSE

The study aimed to investigate the contribution of symptom-related and holism-related factors to MHWs.

METHODS

Participants (visitors of an Internet news portal; N = 16152; 64.1 % males) completed a questionnaire assessing MHWs, somatosensory amplification, somatic symptoms, positive and negative affect, spirituality, holistic health beliefs, and various aspects of health care utilization (both conventional and alternative).

RESULTS

Exploratory factor analysis with oblique rotation revealed two independent dimensions ("Somatic symptom distress" and "Holism") MHWs were involved with factor loadings of 0.294 and 0.417, respectively. The existence of two factors was supported by the results of confirmatory factor analysis. No practically significant interaction between the two factors was found in binary logistic regression analysis. Positive and negative affect, somatosensory amplification, spirituality, and holistic health beliefs were positively connected, while self-rated health status was negatively connected to MHWs even after controlling for socio-demographic and treatment-related variables.

CONCLUSIONS

Holistic thinking and symptom-related behavioral and psychological factors are independently associated with MHWs. Modern health worries can be conceptualized as symptom-related by-products of a holistic-spiritual worldview.

Somatic symptom count scores do not identify patients with symptoms unexplained by disease: a prospective cohort study of neurology outpatients

OBJECTIVE

Somatic symptoms unexplained by disease are common in all medical settings. The process of identifying such patients requires a clinical assessment often supported by clinical tests. Such assessments are time-consuming and expensive. Consequently the observation that such patients tend to report a greater number of symptom has led to the use of self-rated somatic symptom counts as a simpler and cheaper diagnostic aid and proxy measure for epidemiological surveys. However, despite their increasing popularity there is little evidence to support their validity.

METHODS

We tested the score on a commonly used self-rated symptom questionnaire- the Patient Health Questionnaire (PHQ 15) (plus enhanced iterations including an additional 10 items on specific neurological symptoms and an additional 5 items on mental state) for diagnostic sensitivity and specificity against a medical assessment (with 18 months follow-up) in a prospective cohort study of 3781 newly attending patients at neurology clinics in Scotland, UK.

RESULTS

We found 1144/3781 new outpatients had symptoms that were unexplained by disease. The patients with symptoms unexplained by disease reported higher symptoms count scores (PHQ 15: 5.6 (95% CI 5.4 to 5.8) vs 4.2 (4.1 to 4.4) p<0.0001). However, the PHQ15 performed little better than chance in its ability to identify patients with symptoms unexplained by disease. The findings with the enhanced scales were similar.

CONCLUSIONS

Self-rated symptom count scores should not be used to identify patients with symptoms unexplained by disease.

Actual and perceived exposure to electromagnetic fields and non-specific physical symptoms: an epidemiological study based on self-reported data and electronic medical records

BACKGROUND

There is continuing scientific debate and increasing public concern regarding the possible effects of electromagnetic fields (EMF) on general population's health. To date, no epidemiological study has investigated the possible association between actual and perceived EMF exposure and non-specific physical symptoms (NSPS) and sleep quality, using both self-reported and general practice (GP)-registered data.

METHODS

A health survey of adult (≥ 18) participants (n=5933) in the Netherlands was combined with the electronic medical records (EMRs) of NSPS as registered by general practitioners. Characterization of actual exposure was based on several proxies, such as prediction models of radiofrequency (RF)-EMF exposure, geo-coded distance to high-voltage overhead power lines and self-reported use/distance of/to indoor electrical appliances. Perceived exposure and the role of psychological variables were also examined.

RESULTS

Perceived exposure had a poor correlation with the actual exposure estimates. No significant association was found between modeled RF-EMF exposure and the investigated outcomes. Associations with NSPS were observed for use of an electric blanket and close distance to an electric charger during sleep. Perceived exposure, perceived control and avoidance behavior were associated with the examined outcomes. The association between perceived exposure was stronger for self-reported than for GP-registered NSPS. There was some indication, but no consistent pattern for an interaction between idiopathic environmental intolerance (IEI-EMF) and the association between actual exposure and NSPS.

CONCLUSIONS

In conclusion, there is no convincing evidence for an association between everyday life RF-EMF exposure and NSPS and sleep quality in the population. Better exposure characterization, in particular with respect to sources of extremely low frequency magnetic fields (ELF-MF) is needed to draw more solid conclusions. We argue that perceived exposure is an independent determinant of NSPS.

Modern health worries, somatosensory amplification and subjective symptoms: a longitudinal study : a longitudinal study

BACKGROUND

Modern health worries (MHWs; i.e., concerns about possibly harmful features of modern life) have been associated with somatic symptoms and somatosensory amplification in previous cross-sectional studies. Causal relationship among these variables is yet to be discovered.

PURPOSE

The study investigates the temporal association among subjective symptoms, somatosensory amplification (SSA), and modern health worries (MHWs).

METHOD

Baseline and follow-up questionnaires (somatic symptoms--PHQ-15, somatosensory amplification scale--SSAS, modern health worries scale--MHW, PANAS negative affect scale-NA) were completed by 366 undergraduate students in a 2-month longitudinal study.

RESULTS

MHWs were predicted by baseline MHWs (β = 0.721, p < 0.001) and by somatic symptoms (β = 0.084, p < 0.05). Somatic symptoms were predicted by baseline symptoms (β = 0.610, p < 0.001), NA (β = 0.104, p < 0.05), and SSAS scores (β = 0.089, p < 0.05). The only predictor of SSA was baseline SSAS score (β = 0.628, p < 0.001).

CONCLUSION

Based on the results, a linear model (proneness to somatosensory amplification leads to subjective symptoms which lead to MHWs) was proposed, where MHWs serve as explanations of physical symptoms or as possible environmental threats to avoid.

Family background of modern health worries, somatosensory amplification, and health anxiety: A questionnaire study

In the development of somatosensory amplification, health anxiety, and modern health worries, environmental factors seem more important than genetic background. Parental attitudes might represent a major source of learning. In total, 186 adolescents and their parents completed a questionnaire assessing modern health worries, somatosensory amplification, health anxiety, and somatic symptoms. Adolescents’ modern health worries, somatosensory amplification, and health anxiety were positively related to respective parental characteristics in regression analyses even after controlling for sociodemographic variables and somatic symptoms. Parental beliefs may play a role in the development of these characteristics.

Assessing modern health worries: Dimensionality and factorial invariance across age and sex of the Modern Health Worries Scale in a general population sample

Previous work suggests a four-factor structure of the Modern Health Worries Scale. This study is the first to investigate its dimensionality and factorial invariance across age and sex in a representative population sample ( N = 2524) using confirmatory factor analysis. The proposed four-factor model failed to achieve good model fit. Model fit was optimized by allowing correlating error terms resulting in acceptable model fit. Multi-group analysis revealed invariance across age and sex. Our study proved the proposed four-factor structure across age and sex. Consequently, the Modern Health Worries Scale can be applied in general population surveys using subscale scores.

Rasch scalability of the somatosensory amplification scale: a mixture distribution approach

OBJECTIVE

Somatosensory amplification refers to a person's tendency to experience somatic sensations as inappropriately intense and involves hypervigilance concerning bodily sensations. We applied the Somatosensory Amplification Scale (SSAS) in an Internet sample of young adults (N=3031) to test whether the SSAS is Rasch scalable.

METHODS

We applied mixture distribution extensions of the partial credit and rating scale models to identify possible subgroups that use the response set of the SSAS in different ways.

RESULTS

A partial credit model, with two latent classes, showed a superior fit to all other models. Still, one of the SSAS items had to be removed because it showed severe underfit. Overall fit of the remaining items was acceptable, although the differentiation between at least two of the five item categories was questionable in both classes. Class 1 was characterized by a higher SSAS sum score, female gender, more somatic complaints, more anxiety, more psychosocial stress, and slightly higher depressiveness. Further exploratory analyses showed that the three mid categories of the SSAS can be collapsed without a large loss of information.

CONCLUSIONS

Our results show that a shortened version of the SSAS is Rasch scalable but also reveal that there is a lot of room for further improvements of the scale. Based on our results, Item 1 should be removed from the scale and a reduction of the number of response categories is probably warranted.

Modern health worries, subjective somatic symptoms, somatosensory amplification, and health anxiety in adolescents

The cross-sectional study aimed at the psychometric evaluation of the Modern Health Worries Scale in adolescents and the exploration of the relationship among modern health worries, somatosensory amplification, health anxiety, and somatic symptoms. A total of 480 secondary school students (aged between 14 and 19 years) completed a set of questionnaires. Four-factor structure of the scale was confirmed by confirmatory factor analysis. Modern health worries were connected to somatosensory amplification and health anxiety, and somatosensory amplification and health anxiety were partial mediators of the connection between modern health worries and somatic symptoms. Perceived vulnerability (conceptualized as somatosensory amplification and health anxiety) appears to build a “social-cognitive-emotional bridge” between symptoms and modern health worries.

Disturbed dreaming and sleep quality: altered sleep architecture in subjects with frequent nightmares

Nightmares are intense, emotionally negative mental experiences that usually occur during late-night sleep and result in abrupt awakenings. Questionnaire-based studies have shown that nightmares are related to impaired sleep quality; however, the polysomnographic profile of nightmare subjects has been only scarcely investigated. We investigated the sleep architecture of 17 individuals with frequent nightmares and 23 control subjects based on polysomnographic recordings of a second night spent in the laboratory after an adaptation night. Nightmare subjects in comparison with control subjects were characterized by impaired sleep architecture, as reflected by reduced sleep efficiency, increased wakefulness, a reduced amount of slow wave sleep, and increased nocturnal awakenings, especially from Stage 2 sleep. While these differences were independent of the effects of waking psychopathology, nightmare subjects also exhibited longer durations of REM sleep that was mediated by heightened negative affect. Our results support that nightmares are related to altered sleep architecture, showing impaired sleep continuity and emotion-related increase in REM propensity.

Idiopathic environmental intolerance attributed to electromagnetic fields (IEI-EMF) and electrosensibility (ES) - are they connected?

INTRODUCTION

The tendency of experiencing unpleasant symptoms in the proximity of working electric devices is called idiopathic environmental intolerance attributed to electromagnetic fields (IEI-EMF). Evidence about psychophysiological backgrounds of the phenomenon (i.e., detection ability and mechanisms of symptom generation) is not yet conclusive.

METHODS

Participants of the provocation experiment were 29 individuals with self-reported IEI-EMF and 42 control persons. Participants completed questionnaires (symptom expectations, somatosensory amplification - SSAS, modern health worries radiation subscale - MHW-R), and attempted to detect the presence of 50 Hz 0.5 mT magnetic field (MF) directed to their right arm in 20 subsequent 1-min sessions. Heart rate was also recorded and various indices of heart rate variability (HF, LF/HF, SDNN) were calculated.

RESULTS

Using the methodology of the signal detection theory, individuals with IEI-EMF as opposed to the control group showed a higher than random detection performance (d' differed slightly but statistically significantly from zero), and they used a significantly lower criterion (β value) when deciding about the presence of the MF. Detection sessions followed by correct decisions (hits or correct rejections) were characterized by higher HRV (SDNN and HF indices) than periods followed by errors (misses or false alarms). Previous expectations and affiliation to the IEI-EMF group were significant predictors of symptoms reported following exposure. IEI-EMF was closely related to MHW-R and SSAS scores.

CONCLUSION

Detection of MF might be possible for people with IEI-EMF to some extent. Although heightened sensibility to MFs may play a role in the development and/or in the perpetuance of the IEI-EMF phenomenon, symptoms attributed to the MF seem to be mainly of psychogenic origin.

The relationship of modern health worries to depression, symptom reporting and quality of life in a general population survey

OBJECTIVE

Worries about the risk to personal health from new technology and features of modern life have been shown to be associated with the use of health care services, health behaviours, mood and reporting of physical symptoms. We examined the frequency and nature of these concerns in a large national sample and the relationship of modern health worries to demographic factors, depression, symptom reporting and health-related quality of life.

METHODS

A representative sample of the German population (n=2485) completed a face-to-face survey which included demographic information, the Modern Health Worries Scale, as well as measures of depression, symptom reporting, and health-related quality of life.

RESULTS

The majority of the population reports high or extremely high concerns about aspects of modernity affecting their personal health, while only six percent reported no concerns at all. Higher levels of modern health worries were found in females but were not associated with income or age. Higher levels of modern health worries were significantly associated with depression, symptom reporting and lower health-related quality of life. We found the relationship between modern health worries and both symptom reporting and health-related quality of life was only partially explained by depression for most outcome variables, while the association between MHW and physical component (SF-12) was fully mediated by depression.

CONCLUSIONS

Concerns about aspects of modernity affecting health are common in a general population sample and associated with depression, symptom reporting and quality of life.