Can explicit suggestions about the harmfulness of EMF exposure exacerbate a nocebo response in healthy controls? 2018, Verrender et al

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https://www.sciencedirect.com/science/article/pii/S0013935118303347?via=ihub

Environmental Research
Volume 166, October 2018, Pages 409-417

Can explicit suggestions about the harmfulness of EMF exposure exacerbate a nocebo response in healthy controls?
Author links open overlay panelAdamVerrenderab
Sarah P.LoughranabcAnnaDaleckibcFrederikFreudensteinabcRodney J.Croftabc
https://doi.org/10.1016/j.envres.2018.06.032Get rights and content

Highlights


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Results do not support a relationship between radiofrequency exposure and symptoms.

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Healthy participants exhibited a nocebo response during believed radiofrequency exposure.

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Awareness and belief are crucial in the presentation of symptoms.

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The nocebo response may be exacerbated by alarmist media reports.



Abstract
While there has been consistent evidence that symptoms reported by individuals who suffer from Idiopathic Environmental Intolerance attributed to Electromagnetic Fields (IEI-EMF) are not caused by EMF and are more closely associated with a nocebo effect, whether this response is specific to IEI-EMF sufferers and what triggers it, remains unclear. The present experiment tested whether perceived EMF exposure could elicit symptoms in healthy participants, and whether viewing an ‘alarmist’ video could exacerbate a nocebo response. Participants were randomly assigned to watch either an alarmist (N = 22) or control video (N = 22) before completing a series of sham and active radiofrequency (RF) EMF exposure provocation trials (2 open-label, followed by 12 randomized, double-blind, counterbalanced trials). Pre- and post-video state anxiety and risk perception, as well as belief of exposure and symptom ratings during the open-label and double-blind provocation trials, were assessed. Symptoms were higher in the open-label RF-ON than RF-OFF trial (p < .001). No difference in either symptoms (p = .183) or belief of exposure (p = .144) was observed in the double-blind trials. Participants who viewed the alarmist video had a significant increase in symptoms (p = .041), state anxiety (p < .01) and risk perception (p < .001) relative to the control group. These results reveal the crucial role of awareness and belief in the presentation of symptoms during perceived exposure to EMF, showing that healthy participants exhibit a nocebo response, and that alarmist media reports emphasizing adverse effects of EMF also contribute to a nocebo response.

Keywords
Electromagnetic hypersensitivity
Idiopathic environmental intolerance attributed to electromagnetic fields (IEI-EMF)
Media reports
Medically unexplained symptoms
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Participants who viewed the alarmist video had a significant increase in symptoms (p = .041), state anxiety (p < .01) and risk perception (p < .001) relative to the control group.
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Occam's razor says the obvious is rather that the assessment of anxiety-related symptoms by questionnaire is a lousy measurement subject to manipulation and is about as reliable as asking participants to self-rate their current blood oxygen saturation.

Those questionnaires are always biased in favor of producing false positives and always mix up different concepts into a desired meaning. Zero surprise here. Psychometrics are informative but they are not definitive, essentially useless without validation from objective measures.
 
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