Olfactory and Brain Stimulations in Treatment-resistant Depression

NCT ID: NCT05661383

Last Updated: 2025-07-24

Study Results

Results pending

The study team has not published outcome measurements, participant flow, or safety data for this trial yet. Check back later for updates.

Basic Information

Get a concise snapshot of the trial, including recruitment status, study phase, enrollment targets, and key timeline milestones.

Recruitment Status

RECRUITING

Clinical Phase

NA

Total Enrollment

80 participants

Study Classification

INTERVENTIONAL

Study Start Date

2024-01-27

Study Completion Date

2027-10-02

Brief Summary

Review the sponsor-provided synopsis that highlights what the study is about and why it is being conducted.

This is a prospective, randomized, double-blind, parallel-group controlled trial. The aim of this research project is to compare the clinical benefits achieved in patients with major depressive disorder (MDD) following two types of intervention: iTBS active alone or iTBS active combined with olfactory stimulations.

Detailed Description

Dive into the extended narrative that explains the scientific background, objectives, and procedures in greater depth.

Major depressive disorder (MDD) is the most widespread psychiatric disorder, affecting 5% of adults according to the World Health Organization. Anhedonia, defined as the loss of the ability to experience pleasure, is one of the key symptoms of depression, possibly due to a dysfunction of the reward system. Intermittent theta-burst stimulation (iTBS) targeting the dorsolateral prefrontal cortex (DLPFC) has been demonstrated as an emerging treatment option for treatment-resistant depression. One explanation is that iTBS could work through modulating the reward system (increasing dopamine release). One way to improve the therapeutic benefits of non-invasive brain stimulation is to combine it with other therapeutic strategies. Interestingly, olfactory training -daily short-term exposure to pleasant odors- improves significantly depressive symptoms in MDD patients. Indeed, the olfactory system and the reward system are closely related through the olfactory tubercle, which is in the ventral striatum and directly connected to the ventral tegmental area.

The general aim of this research project is to test whether a combination of iTBS targeting the left DLPFC with an olfactory training can improve treatment outcome in MDD, compared to iTBS targeting the left DLPFC alone.

The investigators hypothesize that combining iTBS treatment on DLPFC with hedonic olfactory stimulation potentiates the effect of iTBS treatment administered alone on depressive symptoms, especially anhedonia (physical, social or olfactory). Moreover, the investigators also hypothesize that the superiority of the combined approach is underpinned by greater modulation of connectivity activity and strength between brain regions involved in dopaminergic transmission, compared with iTBS alone.

Conditions

See the medical conditions and disease areas that this research is targeting or investigating.

Treatment-resistant Depression

Study Design

Understand how the trial is structured, including allocation methods, masking strategies, primary purpose, and other design elements.

Allocation Method

RANDOMIZED

Intervention Model

PARALLEL

This is a prospective, single-center, randomized, double-blind, parallel-group controlled trial with two arms
Primary Study Purpose

TREATMENT

Blinding Strategy

TRIPLE

Participants Investigators Outcome Assessors
Patients will be block randomized (1:1) to receive either iTBS active combined with an olfactory stimulation or TBS active alone. Computer generated random numbers will be used to generate the allocation sequence. The allocation sequence will be handled by an independent person from the Administrative Department of the Hospital and will be unavailable to those who enroll and assign patients. Patients will be blind to their treatment assignment. Moreover, the medical doctors who will administer the clinical scales and the researchers that will analyze the data will be blinded to the allocation.

Study Groups

Review each arm or cohort in the study, along with the interventions and objectives associated with them.

iTBS active combined with an olfactory stimulation

Non-invasive brain stimulation protocol (intermittent theta burst protocol (iTBS)) combined with pleasant odors delivered during the iTBS procol.

Group Type EXPERIMENTAL

Non-invasive brain stimulation protocol (intermittent theta burst protocol (iTBS)) combined with pleasant odors delivered during the iTBS procol.

Intervention Type DEVICE

Device: MagPro X100 (MagVenture, Mag2Health, France) iTBS protocol targeting the left dorsolateral prefrontal cortex: 50 consecutive sessions allocated on 10 days (i.e., 5 sessions per working day, 1 hour apart, for 2 weeks).

One iTBS session: burst of 3 pulses at 50 Hz repeated at 200 ms intervals for 2 s (i.e., at 5 Hz) at an intensity of 90% of rMT. A 2 s train of iTBS will be repeated every 10 s for a total of 1800 pulses per session.

Pleasant odorants will be delivered using passive diffusers placed in the room dedicated to the iTBS protocol, during the all-treatment duration. During the inclusion phase, 10 odors known to be pleasant will be presented to the subject. The 3 best rated by the subject will be chosen for olfactory stimulations. During the iTBS session, a randomly selected odor from the 3 will be presented at the same time as the iTBS treatment.

iTBS active alone

Non-invasive brain stimulation protocol (intermittent theta burst protocol (iTBS)) delivered alone.

Group Type ACTIVE_COMPARATOR

Non-invasive brain stimulation protocol (intermittent theta burst protocol (iTBS)) delivered alone.

Intervention Type DEVICE

Device: MagPro X100 (MagVenture, Mag2Health, France) iTBS protocol targeting the left dorsolateral prefrontal cortex: 50 consecutive sessions allocated on 10 days (i.e., 5 sessions per working day, 1 hour apart, for 2 weeks).

One iTBS session: burst of 3 pulses at 50 Hz repeated at 200 ms intervals for 2 s (i.e., at 5 Hz) at an intensity of 90% of rMT. A 2 s train of iTBS will be repeated every 10 s for a total of 1800 pulses per session.

Interventions

Learn about the drugs, procedures, or behavioral strategies being tested and how they are applied within this trial.

Non-invasive brain stimulation protocol (intermittent theta burst protocol (iTBS)) combined with pleasant odors delivered during the iTBS procol.

Device: MagPro X100 (MagVenture, Mag2Health, France) iTBS protocol targeting the left dorsolateral prefrontal cortex: 50 consecutive sessions allocated on 10 days (i.e., 5 sessions per working day, 1 hour apart, for 2 weeks).

One iTBS session: burst of 3 pulses at 50 Hz repeated at 200 ms intervals for 2 s (i.e., at 5 Hz) at an intensity of 90% of rMT. A 2 s train of iTBS will be repeated every 10 s for a total of 1800 pulses per session.

Pleasant odorants will be delivered using passive diffusers placed in the room dedicated to the iTBS protocol, during the all-treatment duration. During the inclusion phase, 10 odors known to be pleasant will be presented to the subject. The 3 best rated by the subject will be chosen for olfactory stimulations. During the iTBS session, a randomly selected odor from the 3 will be presented at the same time as the iTBS treatment.

Intervention Type DEVICE

Non-invasive brain stimulation protocol (intermittent theta burst protocol (iTBS)) delivered alone.

Device: MagPro X100 (MagVenture, Mag2Health, France) iTBS protocol targeting the left dorsolateral prefrontal cortex: 50 consecutive sessions allocated on 10 days (i.e., 5 sessions per working day, 1 hour apart, for 2 weeks).

One iTBS session: burst of 3 pulses at 50 Hz repeated at 200 ms intervals for 2 s (i.e., at 5 Hz) at an intensity of 90% of rMT. A 2 s train of iTBS will be repeated every 10 s for a total of 1800 pulses per session.

Intervention Type DEVICE

Eligibility Criteria

Check the participation requirements, including inclusion and exclusion rules, age limits, and whether healthy volunteers are accepted.

Inclusion Criteria

* had a primary diagnosis of single-episode or recurrent non-psychotic major depressive disorder according to Diagnostic and Statistical Manual of Mental Disorders, fifth edition (DSM-5) criteria;
* scored 20 or over on the MADRS (Montgomery-Åsberg Depression Rating Scale) (Montgomery and Åsberg, 1979) and scored higher than 2 on the MADRS item 8 anhedonia factor score;
* a stable antidepressant medication for 4 weeks prior to inclusion; be able to speak and read French;
* sign a consent form before intervention.

Exclusion Criteria

* a pre-existing condition that affects olfaction including congenital anosmia, upper respiratory tract infection, nasal and/or sinus disease, brain injury or nasal surgery; a neurological disease;
* other comorbid psychiatric disorders or substance abuse (except tobacco);
* contraindications to TMS (medical devices implanted or metallic foreign body in the head);
* pregnant or lactating mothers (controlled by urine pregnancy tests);
* measure of protection or guardianship of justice.
Minimum Eligible Age

18 Years

Eligible Sex

ALL

Accepts Healthy Volunteers

No

Sponsors

Meet the organizations funding or collaborating on the study and learn about their roles.

Fondation de France

OTHER

Sponsor Role collaborator

Hôpital le Vinatier

OTHER

Sponsor Role lead

Responsible Party

Identify the individual or organization who holds primary responsibility for the study information submitted to regulators.

Responsibility Role SPONSOR

Principal Investigators

Learn about the lead researchers overseeing the trial and their institutional affiliations.

BRUNELIN JEROME, PhD

Role: PRINCIPAL_INVESTIGATOR

hospital le vinatier

Locations

Explore where the study is taking place and check the recruitment status at each participating site.

CH Le Vinatier

Bron, , France

Site Status RECRUITING

Countries

Review the countries where the study has at least one active or historical site.

France

Central Contacts

Reach out to these primary contacts for questions about participation or study logistics.

SARTELET Lydie

Role: CONTACT

0437915531 ext. +33

Facility Contacts

Find local site contact details for specific facilities participating in the trial.

BRUNLIN Jérôme, PhD

Role: primary

0437915565 ext. +33

References

Explore related publications, articles, or registry entries linked to this study.

Imbert L, Neige C, Dumas M, Bensafi M, Mandairon N, Brunelin J. Combining pleasant Olfactory and BRAin stimulations in treatment-resistant depression (COBRA): study protocol for a randomized controlled trial. Front Psychol. 2024 Dec 17;15:1451096. doi: 10.3389/fpsyg.2024.1451096. eCollection 2024.

Reference Type DERIVED
PMID: 39744036 (View on PubMed)

Other Identifiers

Review additional registry numbers or institutional identifiers associated with this trial.

2022-A01967-36

Identifier Type: -

Identifier Source: org_study_id

More Related Trials

Additional clinical trials that may be relevant based on similarity analysis.