NCT05940324 · Stanford University
Examining Mu Opioid Mechanisms of Ketamine's Rapid Effects in OCD (MKET2)
(MKET2)
What this study is about
The purpose of this study is to understand how ketamine works in the brain to bring about a reduction in OCD symptoms.
View original scientific description
The purpose of this study is to understand how ketamine works in the brain to bring about a reduction in OCD symptoms.
Interventions
DRUG
Ketamine
Ketamine is an FDA-approved dissociative anesthetic.
DRUG
Naltrexone Pill
Naltrexone is an oral opioid antagonist approved by the Food and Drug Administration (FDA) to treat both alcohol use disorder (AUD) and opioid use disorder (OUD)
OTHER
Placebo pill
An oral inactive placebo pill will be administered to preserve the blinded nature of the study.
Primary outcome measures
Change in the severity of OCD symptoms as measured by the Yale-Brown Obsessive Compulsive Scale (YBOCS)
Time frame: Baseline (Visit 2) to Post Infusion fMRI scan (Visit 4; Day 1), up to 1 week
Change in OCD severity is measured by the YBOCS (Yale Brown Obsessive-Compulsive Scale), a gold standard measure of obsessions and compulsions. For the YBOCS the minimum units are 0 and Maximum units on the total scale are 40. The higher the number on the YBOCS, the more severe the symptoms. Response is defined as at least a 35% reduction on the YBOCS.
Who can participate
This study lists these criteria on ClinicalTrials.gov. A study coordinator reviews eligibility during screening — this page does not determine whether you qualify.
Inclusion criteria
- Meet the criteria for OCD diagnosis
- Failed at least 1 prior trial of standard first-line OCD treatment
- Agree to the following lifestyle modifications: comply with requirements for fasting prior to the Experimental Session, not enroll in any other interventional clinical trials during the duration of the study, and commit to medication study procedures.
- Able to provide informed consent
Exclusion criteria
- prior naltrexone or ketamine use/exposure
- Any current or past medical/psychiatric condition that makes participation unsafe in the opinion of the investigator or study physician
- Pregnant or nursing, or able to become pregnant and are not practicing an effective means of birth control
- the presence of metal in the body that is contraindicated for MRI scans Eligibility Criteria for Healthy Volunteers: Inclusion Criteria:
- Able to provide informed consent Exclusion Criteria:
- current or past use of psychotropic medication
- pregnant or nursing females
- the presence of metal in the body that is contraindicated for MRI scans
Where
- Stanford, California
Collaborators
National Institute of Mental Health (NIMH)
Related conditions & keywords
Frequently asked questions
What is a clinical trial?
A clinical trial is a research study that tests new medical treatments, drugs, devices, or procedures to determine their safety and effectiveness. Trials are carefully designed and monitored to protect participants while advancing medical knowledge.
Is it safe to participate?
Clinical trials follow strict safety guidelines and ethical standards. Trials must be reviewed and approved, and participants are closely monitored by medical professionals throughout the study. You can withdraw at any time if you choose.
Will I be compensated?
Many clinical trials offer compensation for your time, travel expenses, and inconvenience. The specific compensation varies by study and will be discussed during the screening process. All study-related medical care is typically provided at no cost to participants.
Will I receive a placebo instead of treatment?
When effective treatment exists, participants typically receive either the standard treatment plus the study intervention, or the standard treatment plus placebo. You would not be denied effective care. Placebos are primarily used when no proven treatment is available, or in addition to standard care. Your trial consent form will clearly explain what treatments you may receive.
Can I leave a trial if I change my mind?
Absolutely. Participation in clinical trials is completely voluntary. You have the right to withdraw from the study at any time, for any reason, without penalty or loss of benefits to which you are otherwise entitled.
How long does a clinical trial last?
Trial duration varies widely depending on the study design and purpose. Some trials last just a few weeks, while others may continue for months or years. The study coordinator will provide specific timeline information during your screening call.
Data: ClinicalTrials.gov · synced Apr 24, 2026 · Source of record for eligibility and locations