Characterization of Olfactory Perception in Post-Traumatic Stress Disorder (TRAUMODO)

The core symptoms of post-traumatic stress disorder (PTSD) include flash backs, intrusive pictures and thoughts related to the traumatic event, hyperalertness, avoidance of traumatic relevant environmental triggers and emotional dysregulation. Some studies suggest that PTSD is also associated with impaired olfactory perception, which seems quite intuitive regarding the close anatomical-functional connections between olfactory and emotional circuits. Furthermore, some studies reported that olfactory stimuli can trigger flashbacks in subjects with PTSD. However, up to know available data is scarce and heterogeneous concerning that topic. The goal of the study is to determine the olfactory phenotype of subjects with PTSD. More precisely, this project aims at filling the above mentioned gap by systematically assessing the olfactory perception of subjects with PTSD along five dimensions: olfactory identity, hedonic value, familiarity, desirability and edibility. As a secondary goal, the relative weight of olfaction compared to the other senses in the relived memories of subjects with PTSD will be assessed.

The investigators here hypothesize a global impairment in olfactory processing (intensity, hedonicity, familiarity and edibility judgments) in PTSD subjects, compared with healthy subjects.

Study Overview

• Status: Not yet recruiting
• Conditions: Post Traumatic Stress Disorder
• Intervention / Treatment: Behavioral: European Test of Olfactory Capabilities (ETOC); Behavioral: Standardized Hedonicity Test; Behavioral: Questionnaires; Behavioral: Odor / trauma association questionnaire

• Study Type: Observational
• Enrollment (Estimated): 40

Contacts and Locations

• Study Contact: Name: VIGNAUD Philippe, MD, PhD; Phone Number: +33472116396; Email: philippe.vignaud@chu-lyon.fr
• Study Contact Backup: Name: GALIA Perrine, CRA; Phone Number: +33472111311; Email: perrine.galia@chu-lyon.fr

Study Locations

• France
  • Lyon, France, 69003
    • Auvergne-Rhône-Alpes Regional Center for Psychotrauma
    • Contact: VIGNAUD Philippe, MD, PhD; Phone Number: +33472116396; Email: philippe.vignaud@chu-lyon.fr
    • Principal Investigator: VIGNAUD Philippe, MD, PhD

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult
• Accepts Healthy Volunteers: No

• Sampling Method: Non-Probability Sample

Study Population

patients aged 18 to 50 suffering from PTSD

Description

Inclusion Criteria:

• Age between 18 to 50
• Subjects with PTSD

Exclusion Criteria:

• Patients with a neurological history such as stroke, head trauma (e.g. exposure to explosions, sports injury…), neurodegenerative disease…
• Any psychiatric condition except PTSD and major depressive disorder
• Current or recent use of psychotropic drugs that may affect olfactory function.
• Any current or remitted addictive disorder.
• Pregnancy and breast-feeding women

Study Plan

How is the study designed?

Number of groups / cohorts

2

Cohorts and Interventions

Group / Cohort	Intervention / Treatment
Patients with PTSD; They are outpatients receiving psychological and medical treatment in the clinical department connected to the inclusion site	Behavioral: European Test of Olfactory Capabilities (ETOC); Investigators will collect the ETOC score in patient of both arms; Behavioral: Standardized Hedonicity Test; To smell 20 odorant solutions and for each odor and evaluate it along five dimensions: familiarity, hedonicity, edibility, desire to smell again, perceived intensity). Each dimension is assessed with a Likert scale (from 1 (not at all) to 9 (extremely)); Behavioral: Questionnaires; Patients with PTSD will have the following questionnaires : PTSD Checklist for Diagnostic and Statistical Manual (DSM)-V (PCL-5), Peri-trauma Dissociation Experience Questionnaire (PDEQ), Patient Health Questionnaire-9 (PHQ9), Snaith-Hamilton Pleasure Scale (SHAPS), Childhood Trauma Questionnaire (CTQ) and Apathy Evaluation Scale (AES); Behavioral: Odor / trauma association questionnaire; Patients with PTSD will have Odor / trauma association questionnaire
Control group; Data from subjects without PTSD included in a previous study	Behavioral: European Test of Olfactory Capabilities (ETOC); Investigators will collect the ETOC score in patient of both arms; Behavioral: Standardized Hedonicity Test; To smell 20 odorant solutions and for each odor and evaluate it along five dimensions: familiarity, hedonicity, edibility, desire to smell again, perceived intensity). Each dimension is assessed with a Likert scale (from 1 (not at all) to 9 (extremely))

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Standardized Hedonicity Test score	Results obtained in patients will be compared to those obtained in control group	at inclusion

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Effects of potential moderators on odor judgement	Analysis of covariance (ANCOVA) to determine the effect of different moderators (age, gender, type of trauma, time elapsed since trauma, type of treatment received, symptom intensity) on olfactory perception	at inclusion
Evaluation of sensory impressions of memories evoked by certain odors.	Sensory impressions: Nature and frequency of sensory descriptions associated with odor-evoked memories	at inclusion
Evaluation of emotional valence of memories evoked by certain odors.	Language analysis: Use of Natural Language Processing (NLP) techniques to assess the emotional valence of odor-evoked memories and recurrent themes in oral responses concerning evoked memories. Analysis of the association of trauma-related odors with the 5 senses	at inclusion

Collaborators and Investigators

• Sponsor: Hospices Civils de Lyon
• Investigators: Principal Investigator: VIGNAUD Philippe, MD, PhD, Auvergne-Rhône-Alpes Regional Center for Psychotrauma

Study record dates

Study Major Dates

• Study Start (Estimated): August 26, 2024
• Primary Completion (Estimated): August 25, 2026
• Study Completion (Estimated): August 25, 2026

Study Registration Dates

• First Submitted: July 2, 2024
• First Submitted That Met QC Criteria: July 2, 2024
• First Posted (Actual): July 10, 2024

Study Record Updates

• Last Update Posted (Actual): July 10, 2024
• Last Update Submitted That Met QC Criteria: July 2, 2024
• Last Verified: June 1, 2024

More Information

Terms related to this study

• Keywords: Post traumatic stress disorder; Olfaction; Odor; Olfactory perception
• Additional Relevant MeSH Terms: Mental Disorders; Trauma and Stressor Related Disorders; Stress Disorders, Traumatic; Stress Disorders, Post-Traumatic
• Other Study ID Numbers: 69HCL24_0189

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No