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Clinical Trial Summary

Idiopathic Environmental Intolerance (IEI) denotes a functional disorder represented by heterogeneous symptoms that sufferers attribute to specific environmental agents and for which there may be no solid evidence of an underlying physiological cause. We are conducting a randomized controlled trial study to compare patients before and after a newly developed cognitive behavioral therapy treatment program for IEI, with respect to behavioral and psychometric variables. The results of this research project are expected to contribute to advancements in the clinical treatment of IEI, as well as to elaborate on existing theoretical models of IEI.


Clinical Trial Description

Introduction: A percentage of the population report various, nonspecific somatic and cognitive symptoms (e.g., headaches, nausea, fatigue, difficulty concentrating...) that they causally attribute to agents in their environments (chemicals, electromagnetic fields, windmills..). This condition is called Idiopathic Environmental Intolerance (IEI). It is proposed that the attribution of symptoms to an environmental agent, and the associated negative expectations is what drives symptom experience. We hypothesize that this, alongside other cognitive biases, are involved in the emergence and maintenance of symptoms. Treatment models have been developed, but no cognitive behavioral therapy was tested on IEI patients. The planned study aims to investigate the feasibility and efficacy of a cognitive behavioral treatment online program, in ameliorating quality of life in a French population of patients suffering from IEI. Methods and analysis: This parallel two-armed, randomized controlled trial, evaluates an 8-week guided intervention against a wait-list control group. It is a hybrid intervention that will include web-based consecutive modules based on disorder-specific cognitive behavioral therapy (CBT) as well as general transdiagnostic principles . Guidance will be provided by trained psychologists with weekly supportive feedback. As part of the "BELIEF" project, the present study aims to recruit n=82 patients indicating symptom attributed to factors in the environment. Assessments will take place at baseline and after intervention completion (12 and 24 weeks after randomization). The primary outcome will be measured by the SF-12 scale for quality of life. Secondary outcomes include symptom perception, severity and distress, eco-anxiety, emotional processing, intolerance to uncertainty and associated mental disorders such as depression and anxiety. Consumption of healthcare services will also be measured. Ethics and dissemination: Ethics approval has been granted. Results from this study will be published in peer-reviewed journals and presented at international conferences. Trial registration number: DRKS00014375 ;


Study Design


Related Conditions & MeSH terms


NCT number NCT05973214
Study type Interventional
Source Institut National de la Santé Et de la Recherche Médicale, France
Contact Victor Pitron, MD, PHD
Phone 0142348608
Email victor.pitron@aphp.fr
Status Not yet recruiting
Phase N/A
Start date September 2024
Completion date December 2026