Zelquistinel or Placebo for the Reduction of Symptoms of Major Depressive Disorder
Recruiting · 34 sites across 19 states
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?
The goal of this clinical trial is to learn if zelquistinel works to treat depression in adults. It will also learn about the safety of zelquistinel.
It is , overseen by an independent and licensed medical staff.
Read the full clinical description
The goal of this clinical trial is to learn if zelquistinel works to treat depression in adults. It will also learn about the safety of zelquistinel. The main questions it aims to answer are: Does zelquistinel reduce depression scores in participants compared to participants who take a placebo (a look-alike tablet that contains no zelquistinel)? What medical problems are observed in participants who take zelquistinel? Participants will take one tablet of zelquistinel or placebo every week for 6 weeks. Participants will visit the clinic every week of the 6 week period to have the severity of their depression evaluated.
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 64 (male or female).
- •Have a diagnosis of major depressive disorder (MDD), either a single episode (lasting at least 8 weeks and up to 24 months) or a recurrent episode.
- •Depression severity must be at least moderately ill (CGI-S score ≥4) at screening and baseline, and HDRS-17 score ≥18 at screening and baseline.
- •Have depression confirmed using DSM-5 diagnostic interviews (site rater plus SCID-5-CT, with extra confirmation by independent raters).
- •Can follow study visits and complete depression assessments, and provide written informed consent.
🚫 You may not be able to join if…
- •Have treatment-resistant major depressive disorder (not enough improvement after ≤25% response to 2+ different approved MDD medications during the current episode).
- •Have bipolar disorder (or related disorders) or certain other DSM-5 diagnoses such as obsessive compulsive disorder, antisocial personality disorder, borderline personality disorder, post-traumatic stress disorder, panic disorder, or attention-deficit/hyperactivity disorder.
- •Have a psychotic disorder, or major depression with psychotic features.
- •Are currently taking certain depression- or brain-related medicines (FDA-approved antidepressants, antipsychotics, mood stabilizers, sedatives, stimulants), or have used esketamine/ketamine/psychedelics recently; medication changes are also restricted.
- •Have certain medical problems like significant kidney dysfunction (eGFR <70), liver test results >1.5× the upper limit of normal (except possible Gilbert’s syndrome exception), or abnormal heart rhythm/interval issues (including QTcF/QTcB too long).
Are you a good fit?
Simplified highlights. The study team always confirms the full details with you.
- ✓Adults roughly 18–64
- ✓Have Depression
- !Some conditions may not be a fit: Obesity / overweight, Kidney disease, 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?
Yes. This treatment has already been through earlier human studies for safety before reaching this stage.
What you need to know before you apply
What is this study testing?+
The goal of this clinical trial is to learn if zelquistinel works to treat depression in adults. It will also learn about the safety of zelquistinel.
Is it safe? Who makes sure of that?+
This is a mid-stage study (Phase 2), looking at safety and whether the treatment works. 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 · NCT06547489 · Locations: Alabama · California · Colorado · Connecticut · Florida · Georgia · Illinois · Kansas · Kentucky · Massachusetts · Nevada · New York · Ohio · Oklahoma · Pennsylvania · Tennessee · Texas · Utah · Washington