SMILE Trial - Imaging Sub-Study

NCT05528718 | Completed

• 1 other identifier: 22-139
• Study Type: observational
• Target: 11
• Locations: 1 country
• Sites: 1

Brief Summary

This is a pilot sub-study of an ongoing trial comparing N2O to midazolam in MDD and will examine neuroimaging correlates of treatment response.

Conditions

Major Depressive Disorder

Outcome Measures

Primary Outcomes (1)

• Brain functional activity and connectivity

  Changes in brain functional activity and connectivity between baseline and after 4 weeks of receiving the intervention, measured by MR imaging.

  4 weeks from the baseline visit

Study Arms (2)

Experimental group

Participants assigned to this intervention arm in the main study will have been administered nitrous oxide at an inspiratory concentration of 50% with concurrent intravenous saline (100mL) for one hour.

Drug: Nitrous oxide gas for inhalation

Placebo group

Participants assigned to this intervention arm in the main study will have been administered 50% oxygen with intravenous midazolam (0.02mg/kg in 100mL) for one hour.

Drug: Midazolam injection

Interventions

Midazolam injection DRUG

This sub-study does not have an intervention and based on the main study the participants who have received N2O will be compared with the midazolam placebo group.

Also known as: 50% oxygen with intravenous midazolam (0.02mg/kg in 100mL)

Placebo group

Nitrous oxide gas for inhalation DRUG

This sub-study does not have an intervention and based on the main study the participants who have received N2O will be compared with the midazolam placebo group.

Also known as: Nitrous oxide at an inspiratory concentration of 50% with concurrent intravenous saline (100mL)

Experimental group

Eligibility Criteria

• Age: 18 Years - 65 Years
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)
• Sampling Method: Non-Probability Sample

Study Population

Patient participants were diagnosed as suffering from major depressive disorder (MDD) that meets the criteria of the Diagnosis and Statistical Manual for Mental Disorders (DSM-5), will be eligible to participate in this data collection study. Participants who have agreed to receive N2O treatments as part of the Interventional Psychiatry Clinical Program at St. Michael's Hospital will be approached and recruited.

You may qualify if:

• Eligible for main nitrous oxide (SMILE) study

You may not qualify if:

• Contraindication for undergoing MRI scans (e.g., hip circumference \< 180 cm or metal in the body)

Sponsors & Collaborators

• Unity Health Toronto: lead

Study Sites (1)

St. Michael's Hospital

Toronto, Ontario, M5B 1M8, Canada

Location

MeSH Terms

Conditions

Depressive Disorder, Major

Interventions

Endothelium-Dependent Relaxing Factors; Inhalation; Midazolam; Oxygen

Condition Hierarchy (Ancestors)

Depressive Disorder; Mood Disorders; Mental Disorders

Intervention Hierarchy (Ancestors)

Vasodilator Agents; Cardiovascular Agents; Therapeutic Uses; Pharmacologic Actions; Chemical Actions and Uses; Respiratory Mechanics; Respiration; Respiratory Physiological Phenomena; Circulatory and Respiratory Physiological Phenomena; Benzodiazepines; Benzazepines; Heterocyclic Compounds, 2-Ring; Heterocyclic Compounds, Fused-Ring; Heterocyclic Compounds; Chalcogens; Elements; Inorganic Chemicals; Gases

Study Officials

• Venkat Bhat, MD MSc

  Unity Health Toronto

  PRINCIPAL INVESTIGATOR

Study Design

• Study Type: observational
• Observational Model: COHORT
• Time Perspective: PROSPECTIVE
• Sponsor Type: OTHER
• Responsible Party: SPONSOR

Study Record Dates

• First Submitted: September 2, 2022
• First Posted: September 6, 2022
• Study Start: March 7, 2023
• Primary Completion: March 30, 2024
• Study Completion: June 14, 2024
• Last Updated: March 27, 2026

Record last verified: 2024-06

Data Sharing

• IPD Sharing: Will not share

Locations

CA (1)