Impact of comorbidity on symptomatology in various types of environmental intolerance in a general Swedish and Finnish adult population.

Comorbidity with various health conditions is common in environmental intolerances (EIs), which restricts understanding for what symptoms that are associated with the intolerance per se. The present objectives were to study (i) prevalence of a broad range of specific symptoms in chemical, building-related, electromagnetic field- (EMF) related, and sound EI, irrespective of comorbidity, (ii) prevalence of symptoms in body systems in exclusive EIs, and (iii) increased risk of symptoms in body systems in exclusive EIs that cannot be referred to functional somatic syndromes, inflammatory diseases or mental disorders. Cross-sectional data (n = 4941) were used from two combined population-based surveys, the Västerbotten (Sweden) and Österbotten (Finland) Environmental Health Studies. Categorization of EI cases and controls were based on self-reports. Symptoms were assessed with the Environmental Hypersensitivity Symptom Inventory, and these were converted to 27 symptoms of the International Classification of Primary Care, 2nd edition, in eight chapters of body systems. The results showed, with few exceptions, that all assessed specific symptoms were significantly more prevalent in all four EIs than in referents. Although a large overlap between EIs, characteristic body system symptoms were eye and respiratory symptoms in chemical and building-related intolerance, skin symptoms in EMF-related intolerance, and general and unspecified, digestive, eye, cardiovascular, neurological, and psychological symptoms in sound intolerance. After controlling for various comorbidities, all studied body system symptoms were positively associated with chemical intolerance, fewer with sound intolerance, only one with building-related intolerance, and none with EMF-related EI. In conclusion, a broad range of symptoms are reported in all four EIs implying common mechanisms, but symptoms of certain body systems are more likely to be reported in a certain EI that cannot be explained by comorbidity.

Psychological models of development of idiopathic environmental intolerances: Evidence from longitudinal population-based data.

The origin of idiopathic environmental intolerances (IEIs) is an open question. According to the psychological approaches, various top-down factors play a dominant role in the development of IEIs. The general psychopathology model assumes a propensity towards mental ill-health (negative affectivity) increases the probability of developing IEIs. The attribution model emphasizes the importance of mistaken attribution of experienced somatic symptoms; thus, more symptoms should lead to more IEIs. Finally, the nocebo model highlights the role of expectations in the development of IEIs. In this case, worries about the harmful effects of environmental factors are assumed to evoke IEIs. We estimated cross-lagged panel models with latent variables based on longitudinal data obtained at two time points (six years apart) from a large near-representative community sample to test the hypothesized associations. Indicators of chemical intolerance, electromagnetic hypersensitivity, and sound sensitivity fit well under a common latent factor of IEIs. This factor, in turn, showed considerable temporal stability. However, whereas a positive association was found between IEIs and increased somatic symptoms and modern health worries six years later, the changes therein could not be predicted as hypothesized by the three psychological models. We discuss the implications of these results, as well as methodological aspects in the measurement and prediction of change in IEIs.

Mental heartbeat tracking and rating of emotional pictures are not related.

Our aim was to conceptually replicate the findings of previous empirical studies showing that people with higher cardiac interoceptive accuracy experience more intense emotions. Apart of the mental heartbeat tracking task of Schandry, Hungarian (n = 46, 76.0% female, mean age 22.28 ± 2.228) and Norwegian (n = 50, 60.0% female, mean age 24.66 ± 3.048) participants rated the arousal and valence evoked by positive, neutral and negative pictures. Multivariate repeated analysis of variance (applying both frequentist and Bayesian approaches) did not reveal any connection between heartbeat perception scores and the subjective ratings (i.e., arousal and valence) of the pictures in any of the two groups. The lack of the expected association between cardioceptive accuracy and arousal might partly be explained by the methodological differences between previous studies and this one; for example, we did not split or preselected the sample based on the performance on the Schandry task and applied a relatively strict instruction (i.e., by encouraging to count felt heartbeats only, and to report zero if no sensations were detected).

Sustained attention is related to heartbeat counting task performance but not to self-reported aspects of interoception and mindfulness.

Although association between sustained attention and various aspects of interoception (i.e. the perception of the body state) seems plausible, research on this subject is scarce. In the present study, 74 undergraduate students (41 females; age: 22.3 ± 4.04 yrs) filled out the Body Awareness Questionnaire, the Mindful Attention Awareness Scale, and the Somatosensory Amplification Scale and completed the Heartbeat Counting Task (HCT), a sensory-perceptual measure of cardiac interoception and the PEBL Continuous Performance Test (CPT) assessing sustained attention. The HCT score showed a weak to moderate negative correlation with the number of commission errors shown in CPT, indicating a lack of response inhibition (frequentist analysis: rs = -0.313, p = 0.008; Bayesian analysis: τb = -0.216, BF10 = 5.865). Questionnaire measures did not show any connection with CPT-performance. These findings suggest that the subjective representation of attentiveness to bodily processes is unrelated to the objectively measured sustained attention. Response inhibition, however, is moderately related to HCT performance.

Examining the Factor Structure and Validity of the Multidimensional Assessment of Interoceptive Awareness.

The goal of this study was to psychometrically evaluate the Multidimensional Assessment of Interoceptive Awareness (MAIA), a popular self-report questionnaire claimed to assess the most important subjective aspects of interoception. We collected data in two samples (N = 644 and N = 1,516) and focused on the factor structure and validity of MAIA, as well as its associations with personality traits. Confirmatory Factor Analysis suggested that six of the eight subscales measure a common general factor of self-reported interoception; two MAIA subscales, Not-Worrying and Not-Distracting were only weakly related to this factor. Whereas the general factor correlated strongly with a measure of perceived attentiveness to normal nonemotive body processes, and moderately with Extraversion, Openness and Conscientiousness, the Not-Worrying factor showed moderate to strong negative correlations with Emotionality, pain catastrophization, and anxiety-related aspects of body focus. Not-Distracting was only weakly associated with the validating scales. Overall, these findings do not support the claimed eight-factor structure of the MAIA but indicate the existence of an overarching general factor. Additionally, this study provides evidence that interoceptive awareness, as measured by the MAIA, is related to, but distinct from personality.

Nocebo effects on motor performance: A systematic literature review.

Directionally opposite to placebo effects are the nocebo effects that negatively impact people's thoughts, feelings, and actions. An important but scarcely studied aspect of everyday functioning is motor performance, in which nocebo effects might impair athletic skills and the much-needed purposeful daily movements and motor actions. The aim of this literature review is to unveil the nocebo effects on motor performance. Searched databases were PubMed, PsycINFO, and SPORTDiscus. Twenty-one articles, reporting 23 studies, met the eligibility criteria for inclusion in the current review. All reports exhibited "some" risk of bias. Of the 23 studies, 14 found a nocebo effect on motor performance, equivocal results emerged from two studies, and negative findings were reported in seven studies. Most (10/12) studies using a between-subjects design have reported a nocebo effect. The mean effect size was 0.60, suggesting a medium-to-large effect of nocebo intervention on motor performance. Based on this review, we conclude that nocebo effects do influence motor performance and can be evoked with negative verbal information. This effect may be more robust than the placebo effect but also depends on the type of motor performance, on the examined sample, and on the nocebo agent. Hence, nocebo effects should be recognized and controlled in empirical research on motor performance, and they should be prevented or extinguished in practical and therapeutic settings. More extensive examination of the nocebo effect on motor performance is warranted, especially using between-subjects research design and a "no agent" control condition.

Validation of the Hungarian PHQ-15. A latent variable approach.

BACKGROUND AND PURPOSE: Somatic symptoms without a clear-cut organic or biomedical background, also called "medically unexplained" or "somatoform" symptoms, are frequent in primary and secondary health care. They are often accompanied by depression and/or anxiety, and cause functional impairment. The Patient Health Question-naire Somatic Symptom Scale (PHQ-15) was developed to measure somatic symptom distress based on the frequency and bothersomeness of non-specific somatic symptoms. The study aimed to (1) evaluate the Hungarian version of the PHQ-15 from a psychometric point of view; (2) replicate the bifactor structure and associations with negative affect described in the literature; and (3) provide the Hungarian clinical and scientific community with reference (normal) values split by sex and age groups. METHODS: PHQ-15, depression (BDI-R), and subjective well-being (WHO-5) scores obtained from a large (n = 5020) and close to representative community sample (Hun-garostudy 2006) were subjected to correlation analysis and linear structural equation modeling. RESULTS: The PHQ-15 showed good internal consistency (Cronbach's α = 0.810; McDonald's ω = 0.819) and moderate to strong correlation with the BDI-R (rs = .49, p < 0.001) and WHO-5 (rs = -.48, p < 0.001). Fit of the bifactor structure was excellent; in independent analyses, the general factor was strongly associated with depression (ß = 0.656±0.017, p < 0.001) and well-being (ß = -0.575±0.015, p < 0.001), whereas the symptom specific factors were only weakly or not related to these constructs. The PHQ-15 score was higher in females and showed a weak positive association with age. The Hungarian PHQ-15 is a psychometrically sound scale which is positively associated with depression and ne-gatively related to subjective well-being. The bifactor structure indicates the existence and meaningfulness of a gene-ral factor representing the affective-motivational component of somatic symptom distress. CONCLUSION: The Hungarian version of the PHQ-15 is a brief and usable tool for the pre-screening of somatization disorder (DSM-IV) or somatic symptom disorder (DSM-5). The reported reference values can be used in the future for both clinical and research purposes.

Somatosensory amplification absorption contribute to electrosensitivity.

BACKGROUND AND PURPOSE: Two trait-like characteristics, somatosensory amplification and absorption, have been associated with symptom reports and idiopathic environmental intolerances in past research. Purpose - As the two constructs are not connected with each other, their independent contribution to symptom reports and electromagnetic hypersensitivity, as well as their interaction can be expected. METHODS: On-line questionnaire. Patients - 506 college students completed an on-line questionnaire assessing absorption, somatosensory amplification, negative affect, somatic symptoms, and electromagnetic hypersensitivity. RESULTS: Somatosensory amplification (ß = 0.170, p < 0.001) and absorption (ß = 0.128, p < 0.001) independently contributed to somatic symptoms after controlling for gender and negative affect (R2 = 0.347, p < 0.001). Similarly, somatosensory amplification (OR = 1.082, p < 0.05) and absorption (OR = 1.079, p < 0.01) independently contributed to electromagnetic hypersensitivity after controlling for somatic symptoms, gender, and negative affect (Nagelkerke R2 = 0.134, p < 0.001). However, no interaction effects were found. CONCLUSION: Somatosensory amplification and absorption independently contribute to symptom reports and electromagnetic hypersensitivity. Conclusion - The findings suggest that psychological mechanisms underlying symptom reports and electromagnetic hypersensitivity might be heterogeneous.

Modern health worries in patients with affective disorders. A pilot study.

Background - Modern health worries (MHWs) are asso-ciated with various indicators of negative affect, conspiracy theories, and paranormal beliefs in healthy individuals. Purpose - The current pilot study aimed to assess MHWs and indicators of negative affect in patients with affective disorders (N = 66), as well as the possible associations between MHWs and paranoid and schizophrenic tendencies. Results - Compared to somatic patients, psychiatric patients showed higher levels of MHWs, somatosensory amplification, health anxiety, and somatic symptoms. Medium level associations between MHWs and paranoid (r = 0.35, p < 0.01) and schizophrenic (r = 0.37, p < 0.01) tendencies were also revealed. Somatosensory amplification (ß = 0.452, p < 0.001) and paranoia (ß = 0.281, p < 0.01) significantly contributed to MHWs in multiple linear regression analysis (R2 = 0.323, p < 0.001). Discussion - High (i.e. pathological) levels of negative affect can impact a number of related characteristics. Non-pathological paranoid tendencies might contribute to MHWs. The identification of paranoid tendencies seems to be relevant for the treatment of psychiatric patients exhibiting MHWs. Conclusion - Patients with affective disorders are characterized by higher levels of modern health worries, health anxiety, and somatosensory amplification. Modern health worries are associated with paranoid tendencies.

The neuropsychophysiology of tingling.

Tingling is a bodily sensation experienced under a variety of conditions from everyday experiences to experimental and therapeutic situations. It can be induced by both peripheral or afferent (external stimulation, peripheral pathology) and higher cognitive (expectation) processes. The paper summarizes the current scientific knowledge on the neurophysiological and psychological concomitants of the tingling sensation. Four possible models are identified and presented: the afferent, the attention-disclosed, the attention-evoked, and the efferent model. Of these, only the attention-disclosed model, i.e., attention discloses the sensation by opening the gate for suppressed sensory information, appears to be able to explain every aspect of the tingling phenomenon. Terminological issues and the possible role of the tingling phenomenon in medically unexplained symptoms, nocebo and placebo reactions, and body-oriented therapeutic interventions are also discussed.

Characteristics of attention-related body sensations. Temporal stability and associations with measures of body focus, affect, sustained attention, and heart rate variability.

AIM: This study investigated the temporal stability and correlates of attention-related body sensations that emerge without external stimulation during rest and due to focused attention on a body part. MATERIALS: To assess attention-related body sensations, participants were asked to focus on a freely chosen body area with closed eyes, and had to report whether the sensation of that area had changed. Self-report questionnaires were used to assess various aspects of body focus (body awareness, body responsiveness, somatosensory amplification, subjective somatic symptoms), and positive and negative affectivity. Previous experiences in body-mind therapies were also measured. PEBL Continuous Performance Test was used to assess sustained attention. Heart rate variability scores were based on a 3-minute long resting heart rate measurement. METHODS: Fifty-eight university students (22.3 ± 3.95 years; 34 females) participated in the study. The stability of attention-related body sensations was measured 8 weeks later on a randomly chosen sub-group (n = 28). RESULTS: Attention-related body sensations showed a mediocre temporal stability (rρ = 0.47, p = 0.012). People reporting attention-related body sensations showed significantly higher body awareness, somatosensory amplification, and resting heart rate; and marginally higher somatic symptoms. No relation was found with body-mind practice, body responsiveness, positive and negative affect, the vagal component of heart rate variability, and performance in the sustained attention task. CONCLUSION: Attention-related sensations are relatively stable over time. They are connected to some, but not to all of the aspects of body focus. Further studies are needed to elaborate the influencing stable and situational factors.

Health anxiety mediates the connection between somatosensory amplification and self-reported food sensitivity.

BACKGROUND AND PURPOSE: The frequency of self-reported food sensitivity (SFS) is increasing, and has a negative impact on the well-being and everyday functioning of the affected people. A considerable proportion of SFS cannot be medically explained. The lack of knowledge of its origin and treatment causes further stress in those affected. Purpose - This study aims to get a better understanding of the psychological background of the condition. METHODS: A non-representative community sample (N=335; age: 35.1±13.18 yrs; 75.8% female) completed an English on-line questionnaire assessing somatosensory amplification, health anxiety, modern health worries (MHWs), beliefs concerning the scientific validity of complementary and alternative medicine (CAM), holistic beliefs on health and illness. RESULTS: In multiple binary logistic regression analyses, SFS were associated with CAM related beliefs, somatosensory amplification, and health anxiety after controlling for age and gender. The connection between somatosensory amplification and SFS were completely mediated by health anxiety. No differences between the two groups were found with respect to MHWs, worries about the harmful effects of various artificial components in food, and holistic health beliefs. Discussion: More positive attitudes toward CAM might be based on the lack of conventional treatment, rather than on higher levels of MHWs or a more holistic worldview. Both the existence of symptoms and the presence of health anxiety might be needed for the development and maintenance of SFS. CONCLUSION: The findings support the notion that somatosensory amplification and health anxiety might play a role in the development and maintenance of SFS.

Somatosensory Amplification Is a Predictor of Self-Reported Side Effects in the Treatment of Primary Hypertension: a Pilot Study.

PURPOSE: Side effects consist of drug-specific and non-specific symptoms. Both components are based on bodily sensations that a person perceives after taking a drug and subsequently attributes to the drug. We suggest that somatosensory amplification (SSA) may explain a proportion of inter-individual differences in reports of side effects that cannot be accounted for by drug-specific safety profiles. This hypothesis was investigated in hypertensive patients starting a new pharmacotherapy. METHOD: This longitudinal study included 50 patients (66 % women, aged 55 ± 14 years) with a diagnosis of primary hypertension. Patients completed the Somatosensory Amplification Scale (SSAS), started to take their new medication, and recorded side effects on a daily basis for 4 weeks. RESULTS: After controlling for age, gender, number of pills taken, and previous personal and family experiences with medication side effects in the regression analyses, SSAS scores remained a significant predictor of reported side effects over the entire study period (weeks 1 and 2: ß = .621, p < .001; weeks 3 and 4: ß = .493, p = .003). In a subsample comprising patients taking the four most commonly used drug regimes, SSAS was a significant predictor of side effects, even when controlling for type of medication. CONCLUSION: In this sample of patients undergoing anti-hypertensive pharmacotherapy, higher SSA scores predicted increased reports of medication side effects. To account for this tendency and to improve compliance with medication regimes, this group may require special education about the nocebo phenomenon.

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.

Modern health worries - the dark side of spirituality?

Modern health worries (MHWs) are widespread in modern societies. MHWs were connected to both negative and positive psychological characteristics in previous studies. The study aimed to investigate the relationships among intuitive-experiential information processing style, spirituality, MHWs, and psychological well-being. Members of the Hungarian Skeptic Society (N = 128), individuals committed to astrology (N = 601), and people from a non-representative community sample (N = 554) completed questionnaires assessing intuitive-experiential information processing style, spirituality, modern health worries (MHWs), and psychological well-being. Astrologers showed higher levels of spirituality, intuitive-experiential thinking, and modern health worries than individuals from the community sample; and skeptics scored even lower than the latter group with respect to all three constructs. Within the community sample, medium level connections between measures of spirituality and the experiential thinking style, and weak to medium level correlations between spirituality and MHWs were found. The connection between MHWs and experiential thinking style was completely mediated by spirituality. Individuals with higher levels of spirituality are particularly vulnerable to overgeneralized messages on health related risks. Official communication of potential risks based on rational scientific reasoning is not appropriate to persuade them as it has no impact on the intuitive-experiential system.

Dispositional aspects of body focus and idiopathic environmental intolerance attributed to electromagnetic fields (IEI-EMF).

Body focus is often considered an undesirable characteristic from medical point of view as it amplifies symptoms and leads to higher levels of health anxiety. However, it is connected to mindfulness, well-being and the sense of self in psychotherapy. The current study aimed to investigate the contribution of various body focus related constructs to acute and chronic generation and maintenance of medically unexplained symptoms (MUS). Thirty-six individuals with idiopathic environmental intolerance to electromagnetic fields (IEI-EMF) and 36 controls were asked to complete questionnaires assessing negative affect, worries about harmful effects of EMFs, health anxiety (HA), body awareness, and somatosensory amplification (SSA), and to report experienced symptoms evoked by a sham magnetic field. Body awareness, HA, SSA, and EMF-related worries showed good discriminative power between individuals with IEI-EMF and controls. Considering all variables together, SSA was the best predictor of IEI-EMF. In the believed presence of a MF, people with IEI-EMF showed higher levels of anxiety and reported more symptoms than controls. In the IEI-EMF group, actual symptom reports were predicted by HA and state anxiety, while a reverse relationship between symptom reports and HA was found in the control group. Our findings show that SSA is a particularly important contributor to IEI-EMF, probably because it is the most comprehensive factor in its aetiology. IEI-EMF is associated with both a fear-related monitoring of bodily symptoms and a non-evaluative body focus. The identification of dispositional body focus may be relevant for the management of MUS.

Day-to-Day Variation of Subjective Sleep Quality and Emotional States Among Healthy University Students--a 1-Week Prospective Study.

BACKGROUND: In spite of the apparently bidirectional relationship between daytime emotions and nocturnal sleep quality, relatively few studies have examined the day-to-day co-variation of daytime emotional states and sleep quality. PURPOSE: In order to address this issue, we used a 7-day prospective design allowing for the simultaneous investigation of the bidirectional link between sleep quality and affective states. METHOD: Seventy-five healthy university students completed a daily log during 7 days, reporting subjective sleep quality after their final morning awakenings. Eight hours later, they completed the Positive and Negative Affect Schedule measuring daytime affective states. Multilevel modeling was applied in order to examine level 1 (day-to-day co-variation of sleep quality and affective states within individuals) as well as level 2 (averaged between-subjects) effects. RESULTS: Individuals reporting poor sleep quality (on average) were characterized by lower positive and higher negative affect during daytime. Similarly, higher positive and lower negative affect (on average) predicted better subjective sleep quality during the assessment period. Moreover, daily ratings of positive and negative affect were related to the subjective sleep quality of the preceding night: On occasions in which participants reported poor (below average) sleep quality, they also reported lower positive and higher negative affect during the day. Nevertheless, daytime positive and negative affective states did not predict subsequent sleep quality ratings. CONCLUSION: These findings suggest daily dynamic associations between subjective sleep quality and next day's emotional states in a group of healthy individuals, while in the inverse, the co-variation between daytime affective states and subsequent sleep quality was not supported.

Is There a Connection Between Electrosensitivity and Electrosensibility? A Replication Study.

BACKGROUND: Among people with idiopathic environmental intolerance attributed to electromagnetic fields (IEI-EMF), a better than random detection ability for a 50-Hz 0.5-mT magnetic field (MF) and a propensity to experience more symptoms than controls was reported in a previous study. PURPOSE: The current study aimed to replicate and clarify these results using a modified experimental design. METHOD: Participants of the provocation experiment were 49 individuals with self-reported IEI-EMF and 57 controls. They completed the questionnaires (symptom expectations, Somatosensory Amplification Scale--SSAS, radiation subscale of the Modern Health Worries Scale--MHWS Radiation) and attempted to detect the presence of the MF directed to their right arm in 20 subsequent 1-min sessions. Symptom reports were registered after each session. RESULTS: Individuals with IEI-EMF as opposed to the control group showed a higher than random detection performance (d' index of signal detection theory), while no difference in their bias (ß index) toward the presence of the MF was found. Predictors of reported symptoms were self-reported IEI-EMF and believed as opposed to actual presence of the MF. People with IEI-EMF reported significantly more symptoms particularly in the believed presence of the MF. IEI-EMF was closely related to MHWS Radiation and SSAS scores. CONCLUSION: People with IEI-EMF might be able to detect the presence of the MF to a small extent; however, their symptom reports are connected to perceived exposure.