Effectiveness of a Cognitive and Behavioral Treatment Program in People With Idiopathic Environmental Intolerance (IEI)

NCT ID: NCT05973214

Last Updated: 2025-08-13

Basic Information

• Recruitment Status: RECRUITING
• Clinical Phase: NA
• Total Enrollment: 82 participants
• Study Classification: INTERVENTIONAL
• Study Start Date: 2024-02-20
• Study Completion Date: 2028-11-30

Brief 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.

Detailed 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

Conditions

Idiopathic Environmental Intolerance

Study Design

• Allocation Method: RANDOMIZED
• Intervention Model: PARALLEL
• Primary Study Purpose: TREATMENT
• Blinding Strategy: SINGLE

Study Groups

CBT

Group Type: EXPERIMENTAL

Cognitive Behavioral Therapy

Intervention Type: BEHAVIORAL

CBT for IEI

Waitlist

Group Type: OTHER

Cognitive Behavioral Therapy

Intervention Type: BEHAVIORAL

CBT for IEI

Interventions

Cognitive Behavioral Therapy

CBT for IEI

Intervention Type: BEHAVIORAL

Eligibility Criteria

Inclusion Criteria

• Aged ≥18 years,
• Present a diagnosis of idiopathic environmental intolerance confirmed by the lead physician at the admission
• Be affiliated to a social security regime.
• Informed Consent

Exclusion Criteria

• Severe depression, delusion disorder or substance use disorder
• No access to internet
• Non-French speakers
• Currently participating to another research on IEI
• Under an exclusion period for another study
• Benefiting from French state aid known as AME
• Deprivation of liberty by court or administrative order
• Hospitalized without consent
• Under protective measures
• Pregnancy and/or breastfeeding

• Minimum Eligible Age: 18 Years
• Eligible Sex: ALL
• Accepts Healthy Volunteers: No

Sponsors

Institut National de la Santé Et de la Recherche Médicale, France

OTHER_GOV

Sponsor Role: lead

Responsible Party

Responsibility Role: SPONSOR

Principal Investigators

Cedric Lemogne, PR, MD

Role: PRINCIPAL_INVESTIGATOR

Institut de Psychiatrie et des Neurosciences de Paris

Locations

Unité de pathologies professionnelles et environnementales, Hôtel-Dieu

Paris, Paris, France

Site Status: RECRUITING

Countries

France

Central Contacts

Victor Pitron, MD, PHD

Role: CONTACT

victor.pitron@aphp.fr

0142348608

Ingrid Zablith

Role: CONTACT

ingrid.zablith@inserm.fr

0142342608

Facility Contacts

Victor Pitron, MD, PhD

Role: primary

victor.pitron@aphp.fr

Ingrid Zablith

Role: backup

ingrid.zablith@inserm.fr

Other Identifiers

2022-A01370-43

Identifier Type: REGISTRY

Identifier Source: secondary_id

C22-19

Identifier Type: -

Identifier Source: org_study_id