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

2018 · Mixed · Moderate evidence

← Research stream

MixedModerate evidencePaper 1962

Study snapshot

Publicationmanual · 2018

Study typerandomized_trial

Reported directionMixed

Evidence ratingModerate

Abstract

Can explicit suggestions about the harmfulness of EMF exposure exacerbate a nocebo response in healthy controls? Adam Verrender A, Loughran SP, Dalecki A, Freudenstein F, Croft RJ. Can explicit suggestions about the harmfulness of EMF exposure exacerbate a nocebo response in healthy controls? Environmental Research,166:409-417. October 2018. Highlights • Results do not support a relationship between radiofrequency exposure and symptoms. • Healthy participants exhibited a nocebo response during believed radiofrequency exposure. • Awareness and belief are crucial in the presentation of symptoms. • 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. sciencedirect.com

Machine Enhanced Logic

AI evidence extraction

Structured fields below were generated from the paper’s abstract and metadata to make the evidence easier to inspect. Automated extraction may be incomplete or incorrect; verify important details against the original paper.

Study typerandomized_trial

Effect directionmixed

PopulationHealthy participants (controls)

Sample size44

ExposureRF

Evidence strengthModerateConfidence: 78% · Peer reviewed: yes

Main findings

In open-label trials, symptoms were higher during RF-ON than RF-OFF (p < .001), consistent with a perceived-exposure/nocebo effect. In randomized double-blind trials, there was no difference in symptoms (p = .183) or belief of exposure (p = .144) between active and sham RF exposure. Viewing an alarmist video increased symptoms (p = .041), state anxiety (p < .01), and risk perception (p < .001) versus a control video.

Outcomes measured

Symptom ratings during RF provocation trials
Belief of exposure
State anxiety
Risk perception

Limitations

RF exposure parameters (e.g., frequency, SAR, duration) not reported in the abstract
Population limited to healthy participants; generalizability to IEI-EMF sufferers unclear
Symptom increase observed in open-label condition suggests expectancy effects; objective physiological outcomes not described in the abstract

View raw extracted JSON

{
  "study_type": "randomized_trial",
  "exposure": {
    "band": "RF",
    "source": null,
    "frequency_mhz": null,
    "sar_wkg": null,
    "duration": null
  },
  "population": "Healthy participants (controls)",
  "sample_size": 44,
  "outcomes": [
    "Symptom ratings during RF provocation trials",
    "Belief of exposure",
    "State anxiety",
    "Risk perception"
  ],
  "main_findings": "In open-label trials, symptoms were higher during RF-ON than RF-OFF (p < .001), consistent with a perceived-exposure/nocebo effect. In randomized double-blind trials, there was no difference in symptoms (p = .183) or belief of exposure (p = .144) between active and sham RF exposure. Viewing an alarmist video increased symptoms (p = .041), state anxiety (p < .01), and risk perception (p < .001) versus a control video.",
  "effect_direction": "mixed",
  "limitations": [
    "RF exposure parameters (e.g., frequency, SAR, duration) not reported in the abstract",
    "Population limited to healthy participants; generalizability to IEI-EMF sufferers unclear",
    "Symptom increase observed in open-label condition suggests expectancy effects; objective physiological outcomes not described in the abstract"
  ],
  "evidence_strength": "moderate",
  "confidence": 0.78,
  "peer_reviewed_likely": "yes",
  "keywords": [
    "radiofrequency",
    "EMF",
    "nocebo",
    "IEI-EMF",
    "provocation study",
    "double-blind",
    "open-label",
    "alarmist media",
    "risk perception",
    "state anxiety"
  ],
  "suggested_hubs": [
    {
      "slug": "who-icnirp",
      "weight": 0.35,
      "reason": "Addresses symptoms attributed to EMF and nocebo effects in provocation trials, relevant to broader EMF health-risk evaluation discussions."
    }
  ]
}

AI can be wrong. Always verify against the paper.

AI-extracted fields are generated from the abstract and metadata and may be incomplete or incorrect. This material is for informational purposes and is not medical advice.

Identifiers and source

DOI: Not supplied
PubMed: Not supplied

Read the original paper →

Related papers

← Back to the Research Library