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

Environmental research · 2020 · Mixed · Moderate evidence

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MixedModerate evidencePaper 2357

Study snapshot

PublicationEnvironmental research · 2020

Study typeother

Reported directionMixed

Evidence ratingModerate

Abstract

Prospective study of nocebo effects related to symptoms of idiopathic environmental intolerance attributed to electromagnetic fields (IEI-EMF) Anne-Kathrin Bräscher, Stefan M Schulz, Omer Van den Bergh, Michael Witthöft. Prospective study of nocebo effects related to symptoms of idiopathic environmental intolerance attributed to electromagnetic fields (IEI- EMF). Environ Res. 2020 Aug 7;110019. doi: 10.1016/j.envres.2020.110019. Highlights • The etiology of idiopathic environmental intolerance attributed to electromagnetic fields (IEI-EMF) is unknown. • Negative information on health effects of sham WiFi radiation induced nocebo effects. • During sham WiFi exposure somatosensation and electrodermal activity were increased. • Interoceptive accuracy moderated the nocebo effect, depending on stimulus intensity. •The nocebo effect was still detectable one week after its induction. Abstract 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-minute 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. pubmed.ncbi.nlm.nih.gov

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 typeother

Effect directionmixed

PopulationGeneral population participants

Sample size65

ExposureRF · Two sessions one week apart; sham WiFi exposure in 50% of trials during a cued exposure experiment

Evidence strengthModerateConfidence: 74% · Peer reviewed: yes

Main findings

Participants showed evidence of a nocebo effect during sham WiFi exposure (increased self-reported intensity and aversiveness and increased electrodermal activity) in both sessions, including one week later. Interoceptive accuracy moderated the nocebo effect depending on stimulus intensity, and no difference was observed between the health-related EMF film and the neutral film.

Outcomes measured

Self-reported intensity of tactile stimulation
Self-reported aversiveness
Electrodermal activity (sympathetic activation)
Somatosensory perception/nocebo effect
Interoceptive accuracy (heartbeat detection paradigm) as moderator

Limitations

Exposure was sham WiFi (no actual EMF exposure)
Frequency, power, and SAR were not reported in the abstract
Participants were recruited from the general population (not necessarily individuals with IEI-EMF)
No difference between negative-information film and neutral film despite the manipulation

View raw extracted JSON

{
  "study_type": "other",
  "exposure": {
    "band": "RF",
    "source": "wi-fi",
    "frequency_mhz": null,
    "sar_wkg": null,
    "duration": "Two sessions one week apart; sham WiFi exposure in 50% of trials during a cued exposure experiment"
  },
  "population": "General population participants",
  "sample_size": 65,
  "outcomes": [
    "Self-reported intensity of tactile stimulation",
    "Self-reported aversiveness",
    "Electrodermal activity (sympathetic activation)",
    "Somatosensory perception/nocebo effect",
    "Interoceptive accuracy (heartbeat detection paradigm) as moderator"
  ],
  "main_findings": "Participants showed evidence of a nocebo effect during sham WiFi exposure (increased self-reported intensity and aversiveness and increased electrodermal activity) in both sessions, including one week later. Interoceptive accuracy moderated the nocebo effect depending on stimulus intensity, and no difference was observed between the health-related EMF film and the neutral film.",
  "effect_direction": "mixed",
  "limitations": [
    "Exposure was sham WiFi (no actual EMF exposure)",
    "Frequency, power, and SAR were not reported in the abstract",
    "Participants were recruited from the general population (not necessarily individuals with IEI-EMF)",
    "No difference between negative-information film and neutral film despite the manipulation"
  ],
  "evidence_strength": "moderate",
  "confidence": 0.74,
  "peer_reviewed_likely": "yes",
  "keywords": [
    "IEI-EMF",
    "idiopathic environmental intolerance",
    "electromagnetic fields",
    "nocebo",
    "sham WiFi",
    "tactile stimulation",
    "electrodermal activity",
    "sympathetic activation",
    "interoceptive accuracy"
  ],
  "suggested_hubs": [
    {
      "slug": "school-wi-fi",
      "weight": 0.35,
      "reason": "Uses sham WiFi exposure as the EMF-related cue/exposure context."
    }
  ]
}

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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: 10.1016/j.envres.2020.110019
PubMed: 32777274

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