Symptoms of Idiopathic Environmental Intolerance associated with chemicals (IEI-C) are positively associated with perceptual anomalies

• Published in: Journal of psychosomatic research 2022-06, Vol.157, p.110808-110808, Article 110808
• Main Authors: Speck, M.J., Witthöft, M.
• Format: Article
• Language: English
• Subjects: Altered perception; Environmental aspects; Etiology; Hallucination; Hallucinations; Idiopathic; Idiopathic environmental intolerance; Intolerance; Magical thinking; Mental disorders; Personality; Personality traits; Predictive coding; Prone; Psychosis; Schizophrenia; Schizotypal personality; Schizotypy; Somatic symptoms; Somatoform disorders; Statistical analysis; Symptoms; Trait anxiety
• ISSN: 0022-3999; 1879-1360
• DOI: 10.1016/j.jpsychores.2022.110808

Idiopathic Environmental Intolerance (IEI; i.e. the experience of somatic symptoms attributed to environmental agents) represents a functional somatic syndrome of unclear aetiology. Based on previous findings that suggest an association between IEI and perceptual anomalies, this study aimed to investigate the relationship between symptoms of IEI associated with chemicals (IEI-C) and facets of the schizotypy spectrum. A cross-sectional study design was used with N = 410 (78.3% female) persons responding to an online survey in which chemical odor sensitivity (COS) and modern health worries (MHW) that are associated with IEI-C, as well as schizotypal personality traits (SPQ), hallucination proneness (LSHS) and delusional ideation (PDI) as core components of the schizotypy spectrum were assessed. Schizotypal traits were found to be significantly positively associated with MHWs (r = 0.20, p = .01), COS (r = 0.23, p = .01), and showed significant positive associations with hallucination proneness. Magical thinking was found to exhibit a significant positive relationship with both MHW (r = 0.17, p = .01) and COS (r = 0.21, p = .01). These small associations between IEI-C and facets of the psychosis spectrum remained significant even after statistically controlling for individual levels of trait anxiety and depression. Schizotypal personality traits, particularly magical thinking, and hallucination proneness, appear positively related to facets of IEI-C. The findings are of relevance for the advancement of theoretical models of IEI. •Past research suggests a psychogenic origin for Idiopathic Environmental Intolerance.•Perceptual anomalies are common in the cognitive perceptual dimension of schizotypy.•Part of the perceptual anomalies are hallucination proneness and magical thinking.•The findings are of relevance for the advancement of theoretical models of IEI.