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

Do somatic symptom distress and attribution predict symptoms associated with environmental factors?

OBJECTIVE

Not much is known on the development of symptoms associated with environmental factors (SAEF), also known as (idiopathic) environmental intolerances. Findings from qualitative studies suggest that appearance of symptoms might be the first step, followed by the acquisition of a specific attribution. The current study investigated cross-sectional and longitudinal (three years) associations between attribution and symptoms with respect to symptoms associated with chemical substances, certain indoor environments (buildings), sounds, and electromagnetic fields (EMFs).

METHODS

We used data from the first two waves of the population-based Västerbotten Environmental Health Study (n = 2336). Participants completed the Patient Health Questionnaire Somatic Symptom Scale (PHQ-15), the Environmental Symptom-Attribution Scale, and answered single questions on the four aforementioned SAEFs.

RESULTS

Using binary logistic regression analyses, all four SAEFs showed significant cross-sectional associations with somatic symptom distress and the respective attribution. In the longitudinal analysis, development of SAEF-Sound and SAEF-Chemicals were predicted by both somatic symptom distress and attribution. SAEF-EMFs was predicted only by attribution, whereas neither somatic symptom distress nor attribution forecasted SAEF-Buildings.

CONCLUSION

Overall, these findings suggest that attribution (i.e., a specific expectation) plays a substantial role in the development and maintenance of many SAEFs.

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.

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.

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.

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.

The Nocebo Effect: A Review of Contemporary Experimental Research

BACKGROUND

Nocebo effect, the occurrence of adverse symptoms fallowing an inactive treatment, is much less understood than its opposite, placebo effect. This systematic review of contemporary studies exploring the nocebo effect focuses on (1) the mechanisms underlying the nocebo effect, (2) the characteristics of participants exhibiting a more intensive nocebo response, and (3) the circumstances that might reduce or prevent the nocebo effect.

METHOD

We included experimental nocebo studies published in English that examined the occurrence of nocebo in various domains (i.e., types of sensations and symptoms) and different levels of nocebo response (e.g., performance, self-assessment) and in different populations of participants (healthy and clinical). Using Web of Science, PsycInfo and PubMed, we identified 25 papers (35 studies) that met our criteria with a total of N = 2614 participants, mostly healthy volunteers.

RESULTS

Nocebo was invoked by manipulating expectations, conditioning or both. A narrative content synthesis was conducted. Nocebo was successfully invoked in a range of domains (e.g., pain, nausea, itch, skin dryness) and levels (sensory, affective, psychological, and behavioral). Various characteristics of the conditioning procedure and participants' emotions, expectations, and dispositions are found to be related to the nocebo response, which sheds insight into the possible mechanisms of the nocebo effect. Strategies successful and unsuccessful in diminishing the nocebo response are identified. Limitations of this review include a small sample of studies.

CONCLUSION

These findings point to the universality of nocebo as well as to the importance of participant characteristics and experimental circumstances in invoking the nocebo effect. Further research should examine the nocebo effect in clinical populations.

Prospective study of nocebo effects related to symptoms of idiopathic environmental intolerance attributed to electromagnetic fields (IEI-EMF)

The exact causes of Idiopathic Environmental Intolerance Attributed to Electromagnetic Fields (IEI-EMF, i.e., experience of somatic symptoms attributed to low-level electromagnetic fields) are still unknown. Psychological causation such as nocebo effects seem plausible. This study aimed to experimentally induce a nocebo effect for somatic symptom perception and examined whether it was reproducible after one week. We also examined whether these effects were associated with increased sympathetic activity and whether interoceptive accuracy (IAcc) moderated these relationships. Participants were recruited from the general population and instructed that electromagnetic exposure can enhance somatosensory perception. They participated twice in a cued exposure experiment with tactile stimulation and sham WiFi exposure in 50% of trials. The two sessions were scheduled one week apart (session 1: N = 65, session 2: N = 63). Before session 1, participants watched either a 6-min film on adverse health effects of EMF or a neutral film on trade of mobile phones. IAcc was assessed with the heartbeat detection paradigm. Electrodermal activity served as a measure of sympathetic activation. Evidence for a nocebo effect (i.e., increased self-reported intensity and aversiveness and electrodermal activity) during sham WiFi exposure was observed in both sessions. IAcc moderated the nocebo effect, depending on stimulus intensity. Contrary to previous findings, no difference emerged between the health-related EMF and the neutral films. Based on negative instructions, somatic perception and physiological responding can be altered. This is consistent with the assumption that IEI-EMF could be due to nocebo effects, suggesting an important role for psychological interventions.

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.

Obimon: An open-source device enabling group measurement of electrodermal activity

Electrodermal activity (EDA) provides the means to gauge the activity of the sympathetic nervous system. Assessment of EDA for research purposes requires measurement systems that are sensitive to small changes in arousal in the full measurement range, collecting, storing, and monitoring data. The objective behind designing a new open-source device was to be able to measure EDA simultaneously on many subjects, monitoring their activity in real time remotely and collecting high precision data suitable for analyses. To assure feasibility of simultaneous measurements on multiple subjects, the devices must be compact and wearable, without compromising data quality. Experiments were carried out using synchronized devices in group and single subject environments. Validity of EDA measurements of Obimon was demonstrated compared to a reference system (Nexus) during a breathing exercise, a short movie, and while exposed to loud computer-generated tones, using Pearson correlation, Passing-Bablok regression, and Bland-Altman analysis. Seamless management of several Obimons and real-time visualization of EDA via Android phone/tablet application from a large number of participants was demonstrated. Based on analyses of the data collected, we conclude that the Obimon device presented here is a valid and feasible tool for collecting EDA in single or multisubject environments.

Placebo- and Nocebo-Effects in Cognitive Neuroenhancement: When Expectation Shapes Perception

Objective: The number of students using prescription drugs to improve cognitive performance has increased within the last years. There is first evidence that the expectation to receive a performance-enhancing drug alone can result in improved perceived and actual cognitive performance, suggesting a substantial placebo effect. In addition, expecting a placebo can result in lower perceived and actual cognitive performance, suggesting a nocebo effect. Yet, the underlying mechanisms of these effects remain to be elucidated. The aim of our study was to investigate whether the expectation of receiving a performance-increasing drug or a performance-impairing drug leads to changes in actual and perceived cognitive performance, compared to a control group without expectation manipulation. Methods: A total of N = 75 healthy adults were recruited for an experiment to "try cognitive performance-modulating drugs." A participant's actual cognitive performance (alertness, working memory, sustained attention, and divided attention) using the standardized test of attentional performance (TAP) as well as their performance expectation were assessed. Participants were randomly assigned in equal numbers to either receiving a placebo performance increasing nasal spray ("Modafinil") or a nocebo performance impairing nasal spray ("Vividrin^®") or no nasal spray (natural history). After placebo/nocebo nasal spray administration, cognitive performance was reassessed. Subsequent to the second assessment, participants rated their perceived change in cognitive performance, as well as adverse symptoms. Results: Unlike hypothesized, a positive or negative performance expectation did not result in changes in actual performance, corresponding to the induced expectation. Participants in the placebo-Modafinil group rated their perceived change in cognitive performance subsequent to the application of the nasal spray significantly better (d = 1.16) compared to the nocebo-Vividrin^® group. Additionally, participants who expected to receive Modafinil felt less tired than participants in the Vividrin^® group (d = 0.96). Conclusion: Manipulation of performance expectation affects the perceived change in performance and tiredness, but not the actual cognitive performance in healthy adults. This may explain why college students use such drugs despite their little impact on actual cognitive functioning.

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.

The Effect of a Single 30-Min Long Term Evolution Mobile Phone-Like Exposure on Thermal Pain Threshold of Young Healthy Volunteers

Although the majority of mobile phone (MP) users do not attribute adverse effects on health or well-being to MP-emitted radiofrequency (RF) electromagnetic fields (EMFs), the exponential increase in the number of RF devices necessitates continuing research aimed at the objective investigation of such concerns. Here we investigated the effects of acute exposure from Long Term Evolution (LTE) MP EMFs on thermal pain threshold in healthy young adults. We use a protocol that was validated in a previous study in a capsaicin-induced hyperalgesia model and was also successfully used to show that exposure from an RF source mimicking a Universal Mobile Telecommunications System (UMTS) MP led to mildly stronger desensitization to repeated noxious thermal stimulation relative to the sham condition. Using the same experimental design, we did not find any effects of LTE exposure on thermal pain threshold. The present results, contrary to previous evidence obtained with the UMTS modulation, are likely to originate from placebo/nocebo effects and are unrelated to the brief acute LTE EMF exposure itself. The fact that this is dissimilar to our previous results on UMTS exposure implies that RF modulations might differentially affect pain perception and points to the necessity of further research on the topic.

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.

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.

The Placebo and Nocebo Phenomena: Their Clinical Management and Impact on Treatment Outcomes

PURPOSE

This overview focuses on placebo and nocebo effects in clinical trials and routine care. Our goal was to propose strategies to improve outcomes in clinical practice, maximizing placebo effects and reducing nocebo effects, as well as managing these phenomena in clinical trials.

METHODS

A narrative literature search of PubMed was conducted (January 1980-September 2016). Systematic reviews, randomized controlled trials, observational studies, and case series that had an emphasis on placebo or nocebo effects in clinical practice were included in the qualitative synthesis. Search terms included: placebo, nocebo, clinical, clinical trial, clinical setting, placebo effect, nocebo effect, adverse effects, and treatment outcomes. This search was augmented by a manual search of the references of the key articles and the related literature.

FINDINGS

Placebo and nocebo effects are psychobiological events imputable to the therapeutic context. Placebo is defined as an inert substance that provokes perceived benefits, whereas the term nocebo is used when an inert substance causes perceived harm. Their major mechanisms are expectancy and classical conditioning. Placebo is used in several fields of medicine, as a diagnostic tool or to reduce drug dosage. Placebo/nocebo effects are difficult to disentangle from the natural course of illness or the actual effects of a new drug in a clinical trial. There are known strategies to enhance clinical results by manipulating expectations and conditioning.

IMPLICATIONS

Placebo and nocebo effects occur frequently and are clinically significant but are underrecognized in clinical practice. Physicians should be able to recognize these phenomena and master tactics on how to manage these effects to enhance the quality of clinical practice.