Idiopathic Environmental IntoleranceBELIEFSNCT05973214
Effectiveness of a Cognitive and Behavioral Treatment Program in People With Idiopathic Environmental Intolerance (IEI)
A study testing Cognitive Behavioral Therapy in people with Idiopathic Environmental Intolerance, run by Institut National de la Santé Et de la Recherche Médicale, France at 1 site in France.
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. Read more about this study
- Who is it for?
- Ages 18 years and older
- Conditions the study is for
- Idiopathic Environmental Intolerance
- What is being tested?
- Cognitive Behavioral Therapy
- Type of treatment
- Lifestyle or therapy programme
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 82 participants
- Where
- 1 siteFrance
- Study dates
- 20 Feb 2024to Nov 2028
- Phase
- Interventional
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 years and older
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- 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
Who cannot join
- 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
Show all 10Show fewer
- Deprivation of liberty by court or administrative order
- Hospitalized without consent
- Under protective measures
- Pregnancy and/or breastfeeding
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
France1 site, 1 recruiting
- Recruiting
Unité de pathologies professionnelles et environnementales, Hôtel-Dieu
Paris, Paris, 75004
Victor Pitron, MD, PhD, victor.pitron@aphp.fr
Ingrid Zablith, ingrid.zablith@inserm.fr
About this study
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.
Read the 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
- Being tested
- Cognitive Behavioral Therapy
- Keywords
- Environmental health, Idiopathic Environmental Intolerance, Cognitive Behavioral Therapy, Functional Disorder, Somatic Symptoms
- Medical subject headings
- Multiple Chemical Sensitivity, Medically Unexplained Symptoms
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Cognitive Behavioral TherapyBehavioural
CBT for IEI
| Study group | Role | What they receive |
|---|---|---|
| CBT | Experimental | Not described Receives: Behavioral: Cognitive Behavioral Therapy |
| Waitlist | Other | Not described Receives: Behavioral: Cognitive Behavioral Therapy |
What is being measured
The primary outcome is the main question the study is designed to answer.
Short Form Health Survey - 12
Measures quality of life with a minimum value of zero and a maximum value of 100. Higher score indicates better outcome.
Measured: T0; 3 Months ; 6 Months
Secondary outcomes (10)
The Somatic Symptom Disorder - B Criteria Scale
Measures criteria for Somatic Symptom Disorder (SSD) and symptoms' burden: The total score ranges between 0 and 48, with a higher score reflecting higher levels of the psychological features of the SSD, or worse outcome.
Measured: T0; 3 Months ; 6 Months
Symptom Interpretation Questionnaire
Measures causal attributions individuals make of common somatic symptoms by using three sub scales: somatic (range 13-36), psychological (range: 13-52), and environmental/normalizing (range: 17-49). Each sub score represents the extent with which each sub scale is endorsed as a possible cause for symptoms (higher score means higher outcome).
Measured: T0; 3 Months ; 6 Months
QEESI (Quick environnemental exposure and sensitivity inventory)
Measures Chemical Sensitivity with 5 subscales: Symptoms, Chemical Intolerances, Other Intolerances, Masking, and Life Impact.
Patients with no intolerance to chemicals only complete the subscales on Symptoms.
Measured: T0; 3 Months ; 6 Months
11-item Electromagnetic Field Sensitivity Scale
Measures sensitivity to Electromagnetic Fields. The score can range from 0 to 54 (high score representing high annoyance/intolerance and worse outcome). Only patients reporting intolerance to Electromagnetic fields complete this questionnaire.
Measured: T0; 3 Months ; 6 Months
Modern Health Worries Scale short (12-item) version
Measures Modern Health Worries (concerns of respondents about modern environmental issues). Scores range from 12 to 60 with higher scores indicating more concern or worse outcome.
Measured: T0; 3 Months ; 6 Months
Climate Change Anxiety Scale
Measures Climate Change Anxiety with scores ranging from 13 to 65 and higher scores indicating higher levels of climate change anxiety, or worse outcome.
Measured: T0; 3 Months ; 6 Months
Hospital Anxiety and Depression scale
Measures Depression and Anxiety. Score ranges from 0 to 21 with higher score representing worse outcome.
Measured: T0; 3 Months ; 6 Months
Short version of the Intolerance of Uncertainty Scale
Measures Intolerance to Uncertainty with total scores ranging from 12 to 60 with higher score representing worse outcome. The total scores encompasses two sub-scales: prospective anxiety and inhibitory anxiety. A greater score in each subscale indicates a greater level of prospective anxiety and inhibitory anxiety.
Measured: T0; 3 Months ; 6 Months
Body Perception Questionnaire - Very Short Form
Measures body awareness and autonomic stress response patterns. Scores range from 12 to 60. Particularly high scores may indicate the autonomic nervous system is frequently activated by stress or chronic threat responses (i.e. worse outcome)
Measured: T0; 3 Months ; 6 Months
Levels of Emotional Awareness Scale 10 item
Measures the Level of Emotional Awareness with a maximum score of 50. Higher scores indicating greater awareness and differentiation in emotions, or better outcome.
Measured: T0; 3 Months ; 6 Months
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted2 Aug 2023
- Study start20 Feb 2024
- Primary completionFeb 2027 (estimated)
- Study completionNov 2028 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (1)Papers the sponsor has linked to this study.
- Other trials for Idiopathic Environmental IntoleranceStudies of the same condition, open and under way.
- More trials run by Institut National de la Santé Et de la Recherche Médicale, FranceThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Model description
- Parallel two-armed randomized controlled study with a waitlist control group.
- Masking
- Single blind
- Who is masked
- Outcomes assessor
- Enrolment
- 82 participants (estimated)
Sponsor and investigators
- Sponsor type
- Other government
- Responsible party
- Sponsor
- Investigators
- Cedric Lemogne, PR, MD, Principal investigator, Institut de Psychiatrie et des Neurosciences de Paris
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT05973214
- Sponsor's protocol ID
- C22-19
- Other IDs
- 2022-A01370-43
- Acronym
- BELIEFS
- Status last verified
- Aug 2025
- First submitted
- 26 Jul 2023
- Last updated
- 13 Aug 2025
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
Publications
Pitron V, Petzke T, Zablith I, Revillot-Tirot M, Forestier-Dupuch C, Ibouchna FZ, Witthoft M, Leger D, Bensefa-Colas L, Van den Bergh O, Lemogne C. Efficacy of cognitive and behavioral therapy (CBT) treatment for individuals living with symptoms associated with environmental factors (SAEF): protocol for a randomized controlled trial. BMC Psychol. 2025 Nov 24;13(1):1296. doi: 10.1186/s40359-025-03564-5.
PubMed 41287001
Study at a glance
From the registry record, last updated by the sponsor on 13 Aug 2025. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Effectiveness of a Cognitive and Behavioral Treatment Program in People With Idiopathic Environmental Intolerance (IEI)
- ClinicalTrials.gov ID
- NCT05973214
- Acronym / sponsor ID
- BELIEFS / C22-19
- Conditions
- Idiopathic Environmental Intolerance
- Keywords
- Environmental health, Idiopathic Environmental Intolerance, Cognitive Behavioral Therapy, Functional Disorder, Somatic Symptoms
- Study type
- Interventional
- Recruitment status
- Recruiting
- Enrolment
- 82 participants (estimated)
- Lead sponsor
- Institut National de la Santé Et de la Recherche Médicale, FranceOther government
- Study start
- 20 Feb 2024 (actual)
- Primary completion
- Feb 2027 (estimated)
- Study completion
- Nov 2028 (estimated)
- First posted
- 2 Aug 2023 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
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
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Single blind (outcomes assessor)
- Number of arms
- 2
- Model description
- Parallel two-armed randomized controlled study with a waitlist control group.
| Arm | Type | Receives |
|---|---|---|
| CBT | Experimental | Behavioral: Cognitive Behavioral Therapy |
| Waitlist | Other | Behavioral: Cognitive Behavioral Therapy |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (4 listed)
- 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
Key exclusion criteria (10 listed)
- 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
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Cognitive Behavioral TherapyCBT for IEI | Behavioural | CBT, Waitlist |
Primary outcome
Short Form Health Survey - 12
Time frame: T0; 3 Months ; 6 Months
Measures quality of life with a minimum value of zero and a maximum value of 100. Higher score indicates better outcome.
10 secondary outcomes
The Somatic Symptom Disorder - B Criteria Scale
Time frame: T0; 3 Months ; 6 Months
Symptom Interpretation Questionnaire
Time frame: T0; 3 Months ; 6 Months
QEESI (Quick environnemental exposure and sensitivity inventory)
Time frame: T0; 3 Months ; 6 Months
11-item Electromagnetic Field Sensitivity Scale
Time frame: T0; 3 Months ; 6 Months
Modern Health Worries Scale short (12-item) version
Time frame: T0; 3 Months ; 6 Months
Climate Change Anxiety Scale
Time frame: T0; 3 Months ; 6 Months
Hospital Anxiety and Depression scale
Time frame: T0; 3 Months ; 6 Months
Short version of the Intolerance of Uncertainty Scale
Time frame: T0; 3 Months ; 6 Months
Body Perception Questionnaire - Very Short Form
Time frame: T0; 3 Months ; 6 Months
Levels of Emotional Awareness Scale 10 item
Time frame: T0; 3 Months ; 6 Months
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 13 Aug 2025.
- Derived from this study: PubMed 41287001Pitron V, Petzke T, Zablith I, Revillot-Tirot M, Forestier-Dupuch C, Ibouchna FZ, Witthoft M, Leger D, Bensefa-Colas L, Van den Bergh O, Lemogne C. Efficacy of cognitive and behavioral therapy (CBT) treatment for individuals living with symptoms associated with environmental factors (SAEF): protocol for a randomized controlled trial. BMC Psychol. 2025 Nov 24;13(1):1296. doi: 10.1186/s40359-025-03564-5.
Related trials for Idiopathic Environmental Intolerance
Active, not recruiting
Central Processing of Odour Stimuli in Patients With Functional Somatic Disorder, MCS or Post Covid Compared to Healthy Controls
Functional Disorder, Bodily Distress Syndrome
Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
Cedric Lemogne, PR, MD principal investigator
Institut de Psychiatrie et des Neurosciences de Paris
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Cognitive Behavioral Therapy in people with Idiopathic Environmental Intolerance, run by Institut National de la Santé Et de la Recherche Médicale, France at 1 site in France.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 4 inclusion and 10 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: looking for participants now, as of the sponsor's last update on 13 Aug 2025. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in France. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact Victor Pitron, MD, PHD (0142348608, victor.pitron@aphp.fr), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Short Form Health Survey - 12 (time frame: T0; 3 Months ; 6 Months). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
On the ClinicalTrials.gov record for NCT05973214, which also lists 1 linked publication.
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 13 Aug 2025.