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Nitrous Oxide for Late-Life Depression - PROTO-BRAIN

Nitrous Oxide for Late-Life Depression : a Randomized Controlled Trial With Comparator - PROTO-BRAIN

Status
Completed
Phases
NA
Study type
Interventional
Source
ClinicalTrials.gov
Registry ID
NCT05007028
Acronym
PROTO-BRAIN
Enrollment
60
Registered
2021-08-16
Start date
2021-11-16
Completion date
2024-12-19
Last updated
2025-11-24

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Late-Life Depression, Resistant Depression, Treatment

Keywords

Nitrous Oxide, Magnetic Resonance Imaging, Ultrasound Tissue Pulsatility Imaging

Brief summary

Resistant Depression is a common condition in older adults and there is an urgent need for novel antidepressant in this population. Nitrous Oxide (N2O) has recently shown rapid antidepressant effect in midlife depression but no study has currently investigated the efficacy and safety of N2O in Late-Life Depression (LLD), while N2O may prove to be an ideal treatment for LLD because of glutamatergic antagonism and cerebrovascular effects and also a relatively good safety profile. The goal of our study is to compare changes in depressive symptoms after 2 hours, 24 hours, 1 week and 2 week of a 1-hour exposure to EMONO (Equimolar Mixture of Oxygen and Nitrous Oxide) versus Medical Air. Secondary Objectives include comparing differences in neuroimaging measures between 3 groups (responders and non-responders in the EMONO group, and patients in the control group).

Detailed description

Secondary objectives include: * To compare changes in Brain Tissue Pulsatility (BTP) as measured with Ultrasound Tissue Pulsatility Imaging (TPI) between responders in the EMONO group (MADRS change of at least 50%), non-responders in the EMONO group (MADRS change of no more than 50%) and in the Air Medical group * To compare baseline differences in structural (brain volumes, white matter hyperintensities) and functional (resting state connectivity in BOLD, Brain Pulsatility in BOLD, Brain Perfusion in ASL) among the 3 groups * To compare changes in depressive and anxiety symptoms between the active and control group, as assess with Hamilton scale, CGI scale, QIDS-SR, VAS and the STAI scale * To compare safety between the active and control group, as assessed with SSI, YMRS, CADSS, BPRS

Interventions

DRUGEMONO

Exposure to 1 hour of EMONO via facial mask

DRUGMedical Air

Exposure to 1 hour of Medical Air via facial mask

Sponsors

University Hospital, Tours
Lead SponsorOTHER

Study design

Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT
Masking
DOUBLE (Subject, Investigator)

Intervention model description

Randomized double blind trial with comparator

Eligibility

Sex/Gender
ALL
Age
60 Years to 90 Years
Healthy volunteers
No

Inclusion criteria

* Aged 60-90 years-old * Major Depressive Episode according to DSM-5 criteria, confirmed by the MINI - Mini International Neuropsychiatric Interview * MADRS score greater than 20 (Montgomery Asberg Depression Rating Scale) * Patient resistant to at least one well-conducted antidepressant treatment, as documented by the MGH-ATRQ scale * Patient who can undergo N2O diffusion via a facial mask * Patient who has signed an informed consent * Person affiliated with a social security scheme

Exclusion criteria

* Bipolar disorder, schizophrenic disorder, neurodegenerative disease, documented by the MINI and the MMSE (non-inclusion if MMSE \< 24/30), addictive disorder * Unstable somatic pathology (including unstable neurological or cardiological diseases at risk of interfering with N2O diffusion) * Presence of active and significant psychotic symptoms, at investigator's discretion * Contraindications to EMONO (50%N2O/ 50%O2) : pneumothorax, emphysema, bowel obstruction, intracranial hypertension, chronic deficiency in vitamin B12 or B9 * Contraindications to MRI, including claustrophobia * Legal incapacity and/or other circumstances unabling the patient to understand the nature, purpose or consequences of the study * A person participating in a drug clinical trial or during a period of exclusion from any clinical study

Design outcomes

Primary

MeasureTime frameDescription
Change in MADRSBaseline, 2 hours, 24 hours, 1 week, 2 weeksmontgomery asberg depression scale for symptoms severity

Secondary

MeasureTime frameDescription
MRIAt BaselineStructural and Functional MRI
Change in HDRS 17 itemsBaseline, 2 hours, 24 hours, 1 week, 2 weeksHamilton Depression Rating Scale
Change in QIDS-SRBaseline, 2 hours, 24 hours, 1 week, 2 weeksQuick Inventory of Depressive Symptomatology Self Report, Depression severity
Change in CGIBaseline, 2 hours, 24 hours, 1 week, 2 weeksClinical Global Impression
Change in VASBaseline, 2 hours, 24 hours, 1 week, 2 weeksVisual Analog Scale for global well-being self assessement
Change in Brain Tissue PulsatilityBaseline and immediately after the interventionIndexes of BTP, including BTP amplitudes
Change in SSIBaseline, 2 hours, 24 hours, 1 week, 2 weeksScale for Suicidal Ideation
Change in YMRSBaseline, 2 hours, 24 hours, 1 week, 2 weeksYoung Mania Rating Scale
Change in Clinician Administered Dissociative States ScaleBaseline, 2 hours, 24 hours, 1 week, 2 weeksCADSS
Change in BPRSBaseline, 2 hours, 24 hours, 1 week, 2 weeksBrief Psychiatric Rating Scale
Change in STAIBaseline, 2 hours, 24 hours, 1 week, 2 weeksState-Trait Anxiety Inventory

Countries

France

Outcome results

None listed

Source: ClinicalTrials.gov · Data processed: Feb 4, 2026