CompletedNot Applicable

Brain Reactivity to Nitrous Oxyde in Depression : an MRI and Ultrasound Study (PROTOBRAIN Pilote)

France30 participantsStarted 2020-02-20

Plain-language summary

Recent evidence suggest that Nitrous Oxyde (N2O) could exhibit antidepressant effect in treatment-resistant depression (TRD). However, the pathophysiology of this effect remains unclear and could include glutamatergic activity but also cerebrovascular effects and changes in brain connectivity. The goal of our study is to characterize brain reactivity to N2O in TRD patients, as assessed with Ultrasound Tissue Pulsatility Imaging (TPI) and Magnetic Resonance Imaging (MRI) (including Arterial Spin Labeling - ASL - for brain perfusion and Blood-Oxygen-Level Dependent - BOLD - for brain connectivity and pulsatility). Ultrasound and MRI Neuroimaging will be measured before, during and after a single one-hour exposure of a 50%N20/50%O2 mixture, in depressed individuals (n=20) and healthy volunteers (n=10). We make the hypothesis that brain reactivity will be lower in depressed individuals nonresponders to N2O compared to responders and healthy controls. This study would provide further characterisation of the pathophysiology of the antidepressant response to N2O, as well as providing potential biomakers (Ultrasound and MRI) for treatment response to N2O in TRD.

Who can participate

Age range

25 Years – 50 Years

Sex

FEMALE

See this in plain English?

AI-rewrites the medical criteria so a patient or caregiver can understand them. Always confirm with the trial site.

Inclusion Criteria: * Inclusion criteria common to all participants * Female between 25 and 50 years of age * A person who can undergo N2O diffusion via a facial mask. * A person who has signed an informed consent. * Person affiliated with a social security scheme. * Inclusion Criteria for Depressive Patients * Major Depressive Episode according to DSM-5 criteria, confirmed by the MINI - International Neuropsychiatric Interview. * Patients with an MADRS score greater than 20 (Montgomery * Asberg Depression Rating Scale). * Patients resistant to at least one well-conducted antidepressant treatment, as documented by the MGH-ATRQ scale. * Absence of: bipolar disorder, schizophrenic disorder, neurodegenerative disease, schizophrenic disorder, neurodegenerative disease, addiction to one or more toxics documented by the MINI. * Inclusion criteria for healthy voluntary controls * Absence of: bipolar disorder, schizophrenic disorder, neurodegenerative disease, schizophrenic disorder, neurodegenerative disease, addiction to one or more toxics documented by the MINI, current or past. Exclusion Criteria: * Unstable somatic pathology (including unstable neurological or cardiological pathologies at risk of interfering with N2O diffusion) * Presence of active and significant psychotic symptoms, at investigator's discretion * Contraindications to mixture 50%N2O/ 50%O2: intracranial hypertension, altered state of consciousness, head trauma, pneumothorax, emphysema bubbles, abdominal gaseo…

Questions worth asking your doctor

Bring these to your next appointment. They're a starting point for a shared conversation — not a sign you qualify or a recommendation to enrol.

1Based on my diagnosis and history, is this trial worth exploring for me — or is there a standard treatment we should try first?
2What does this trial's phase tell us about how much is already known about its safety and benefit?
3What would taking part actually involve for me — visits, tests, time, and travel?
4What are the known and possible risks or side effects I should weigh, and how would they be monitored?
5If this trial isn't the right fit, what other options or trials would you suggest I look into?

Generated to help you prepare — always confirm anything about your own eligibility and care with the study team and your doctor.

Questions for the trial coordinator

The trial coordinator is the person who runs the study day to day. These cover the practical side — logistics, costs, and what taking part would actually mean for your life. The study team confirms whether you meet the criteria; these are questions to ask, not a sign you qualify.

1What does taking part actually involve week to week — how many visits, where, and how long does each one take?
2What costs are covered by the study, and what might I have to pay for myself, including travel, parking, or time off work?
3What happens during screening, and what happens if the study team confirms I don't meet the criteria after those tests?
4Who pays for the scans, blood work, and other tests the trial requires — the study, my insurance, or me?
5How will being in the trial affect my regular care, and will my own doctor stay informed and involved?
6Can I leave the trial at any point if I change my mind, and what would happen to my care if I do?

A starting point for the conversation — always confirm anything about your own eligibility, costs, and care with the study team and your doctor.

What they're measuring

Brain Tissue Pulsatility (BTP) as measured with Ultrasound TPI

Timeframe: 3 months after LVLS

Trial details

NCT IDNCT04199143

SponsorUniversity Hospital, Tours

Sponsor typeOTHER

Study typeINTERVENTIONAL

Primary completion2021-06-10

View on ClinicalTrials.gov More Treatment Resistant Depression trials