Can explicit suggestions about the harmfulness of EMF exposure exacerbate a nocebo response in healthy controls?

Environ Res. 2018 Oct:166:409-417. doi: 10.1016/j.envres.2018.06.032. Epub 2018 Jun 21.

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.

Publication types

  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Double-Blind Method
  • Electromagnetic Fields / adverse effects*
  • Health Knowledge, Attitudes, Practice
  • Humans
  • Multiple Chemical Sensitivity / psychology*
  • Nocebo Effect*
  • Radio Waves
  • Suggestion
  • Video Recording