NMDA Receptor Antagonist Nitrous Oxide Targets Affective Brain Circuits
Recruiting · St Louis, Missouri
Always free
Study care at no cost to you
For your time and travel
Many studies pay you back
Most need no insurance or papers
Legal status usually isn't required; we'll tell you each study's requirements
Interpreters available
Ask for your language
Your choice
Voluntary — you can stop anytime
What is this study?
Most clinical major depression responds to standard treatments (medication and psychotherapy); however, a significant subset of depressed patients (15-20%) do not respond to these treatments and are referred to as treatment-resistant major depression (TRMD). New treatments for TRMD are needed, and one promising line of research are drugs known as N-methyl-D-aspartate (NMDA) glutamate receptor antagonists.
It is , overseen by an independent and licensed medical staff.
Read the full clinical description
Most clinical major depression responds to standard treatments (medication and psychotherapy); however, a significant subset of depressed patients (15-20%) do not respond to these treatments and are referred to as treatment-resistant major depression (TRMD). New treatments for TRMD are needed, and one promising line of research are drugs known as N-methyl-D-aspartate (NMDA) glutamate receptor antagonists. In a recent pilot study, our group demonstrated that the NMDA antagonist nitrous oxide is effective in TRMD. This application proposes to take the next important step in understanding how nitrous oxide exerts its effects in the human brain by using state-of-the-art brain neuroimaging (functional connectivity magnetic resonance imaging) in a group of non-depressed, healthy volunteers and comparing the results to a group of TRMD patients. This study involves exposing approximately 25 non-depressed healthy participants and 25 TRMD participants to nitrous oxide and a placebo gas, to compare their brain images before and after each of the inhalation sessions. Sessions will be separated by at least one month to prevent treatment effects from carrying over into the following session. All willing and eligible subjects will undergo up to six functional connectivity MRI scans, and two inhalation sessions. Functional imaging in the brain will allow us to trace the interconnections between various parts of the brain, including those involved with emotion and depression. Other procedures will involve screening materials to ensure safety of the participants before beginning the study (i.e. no MRI scan contraindications) and that subjects meet eligibility criteria to being in the targeted age range, depression/non-depressed state, neurological disorder history, and no medication exclusions.
Who this study is looking for
In plain language, from the study's own rules. The study team confirms the full details with you — this isn't a final yes or no.
✅ You may be able to join if…
- •Adults age 18 to 65
- •Right-handed
- •Good command of the English language
- •Non-depressed controls must score ≤7 on the Hamilton Depression Rating Scale (HDRS, 17-item) and must not have any history of depression
- •TRMD participants must score ≥17 on the HDRS and have documented failure to respond to 3–4 adequate antidepressant treatments, and have at least one current depressive episode
🚫 You may not be able to join if…
- •Anyone who meets DSM-IV criteria for any Axis I diagnosis (mental health diagnosis), except that TRMD group may have MDD
- •People with known primary neurological disorders or certain serious medical problems, including dementia, stroke, Parkinson’s disease, brain tumors, multiple sclerosis, seizure disorder, or severe heart/lung disease
- •People who cannot have MRI scans (for example, claustrophobia or implanted metal)
- •Controls who are currently using psychotropic medications/antidepressants or other drugs/herbals intended to treat depression or anxiety
- •People who are pregnant or breastfeeding, or who cannot use effective contraception if they could become pregnant
Are you a good fit?
Simplified highlights. The study team always confirms the full details with you.
- ✓Adults roughly 18–65
- ✓Have Depression
- !Some conditions may not be a fit: Anxiety
- !Not for people who are pregnant or breastfeeding
What to expect, step by step
- 1
Usually a few weeks
The study team checks whether the study is a good fit for you, with a visit and sometimes lab tests. You can ask any questions before deciding.
- 2
Treatment
If you join and choose to continue, you receive the study treatment and are watched closely by medical staff.
- 3
Follow-up
After treatment, the team checks on your health and confirms the visit schedule with you. You can leave the study at any point.
Has this treatment been tested before?
This is an early-stage study. The treatment has gone through laboratory and preliminary testing before being studied in people here.
What you need to know before you apply
What is this study testing?+
Most clinical major depression responds to standard treatments (medication and psychotherapy); however, a significant subset of depressed patients (15-20%) do not respond to these treatments and are referred to as treatment-resistant major depression (TRMD). New treatments for TRMD are needed, and one promising line of research are drugs known as N-methyl-D-aspartate (NMDA) glutamate receptor antagonists.
Is it safe? Who makes sure of that?+
This is an early study (Phase 1), focused mostly on safety. Every study is reviewed and monitored by an independent ethics board (called an IRB) whose job is to protect participants, and care is overseen by licensed medical staff. You'll be told the known risks before you agree to anything, and you can stop at any time.
Will I get a placebo instead of the real treatment?+
Some studies compare a treatment against a placebo (an inactive version), and some don't. If this one does, the study team will explain your chances of receiving the active treatment before you decide. Nothing is hidden from you.
Do I have to stop taking my current medications?+
It depends on the study. Some let you stay on your current medications and some ask you to adjust them. Never stop a medication on your own — the study team will review everything with you first.
Does it cost anything? Will I be paid?+
The study treatment and study-related visits are provided at no cost to you. Some studies also pay for your time; the coordinator can tell you if this one does. You should never be asked to pay to take part.
Do I need insurance? Will anyone ask about my immigration status?+
No. You do not need health insurance to take part in a research study, and you will not be asked about your immigration status to join. Taking part is about whether you're a medical fit for the study.
What if English isn't my first language?+
You have the right to understand everything before you agree. Study sites can often provide materials or an interpreter in your language — you can ask the coordinator for one.
Is my information private?+
Yes. Your health information is only shared with the study sites you choose to be contacted by, and only to help match and enroll you. It is never sold, and you can ask us to delete it at any time.
Some requirements (like specific lab values or timing) are confirmed directly by the study team, not by us.
Source: ClinicalTrials.gov · NCT02994433 · Locations: Missouri