Examining Mu Opioid Mechanisms of Ketamine's Rapid Effects in OCD (MKET2)

Examining Mu Opioid Mechanisms of Ketamine's Rapid Effects in OCD (MKET2) (NCT05940324) is a Phase 2 interventional studying Obsessive-Compulsive Disorder, sponsored by Stanford University. RECRUITING as of the most recent ClinicalTrials.gov update. Talk to your doctor before contacting the trial site.

About This Trial

The purpose of this study is to understand how ketamine works in the brain to bring about a reduction in OCD symptoms.

What Stage of Research Is This?

Phase 2 trials evaluate whether a treatment actually works against Obsessive-Compulsive Disorder and continue monitoring side effects. Phase 2 enrolls larger groups (typically 100–300 patients) and produces the first real efficacy signal. A successful Phase 2 readout is what unlocks the much larger Phase 3 confirmatory trials needed for FDA approval.

This trial is currently recruiting participants. The sponsor has registered the study with ClinicalTrials.gov as actively enrolling, which means new applicants who meet the eligibility criteria can be considered for screening. Trial status can change between updates — confirm current recruiting status with the study contact before traveling for a screening visit.

Target enrollment of 150 participants puts this in the typical range for a Phase 2-style efficacy study or a moderate Phase 3 trial in a focused Obsessive-Compulsive Disorder subpopulation. At this scale, the study has enough statistical power to detect a clear treatment effect but is not the largest cohort in the field.

Who May Be Eligible (Plain English)

Eligibility Criteria for Participants with OCD: Who May Qualify: - Ages 18-65 - 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 willing to sign a consent form Who Should NOT Join This Trial: - 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: Who May Qualify: - Ages 18-65 - Able to provide willing to sign a consent form Who Should NOT Join This Trial: - current or past use of psychotropic medication - pregnant or nursing females - the presence of metal in the body that is contraindicated for MRI scans Always talk to your doctor about whether this trial is right for you.

These are translations of the protocol\'s inclusion and exclusion criteria, simplified for patients and caregivers. The original clinical text appears below. Eligibility is ultimately confirmed by the trial site\'s screening process — this summary is a starting point for a conversation with your doctor, not a final determination.

Original Eligibility Criteria

View original clinical language

Eligibility Criteria for Participants with OCD: Inclusion Criteria: * Ages 18-65 * 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: * Ages 18-65 * 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

Treatments Being Tested

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.

Locations (1)

Trial sites listed on ClinicalTrials.gov for this study. Site activation status can vary — confirm with the specific site before traveling for a screening visit.

Department of Psychiatry & Behavioral Sciences

Stanford, California, United States

How to Talk to Your Doctor About This Trial

Bring the printable summary of this trial — including the NCT ID (NCT05940324), the sponsor (Stanford University), and the key eligibility criteria — to your next appointment. Your doctor can review the inclusion and exclusion criteria against your medical history, lab values, and current treatments to assess whether you are likely to qualify. They can also help you weigh whether trial participation makes sense alongside your existing care plan.

Useful questions to walk through together: What does the trial protocol require beyond standard care? How long is the active treatment phase, and how long is follow-up? Are there study visits at sites I can reach? Who pays for the trial-specific procedures, and who pays for standard-of-care portions? See our 25 questions to ask about clinical trials guide for a more complete checklist.

Authoritative Sources

The official record for this trial lives on ClinicalTrials.gov — the federal registry maintained by the National Library of Medicine at NIH. For background on how this trial fits into the FDA approval pathway, see the FDA drug approval process. For oncology-specific guidance for patients considering trials, the National Cancer Institute publishes patient-oriented overviews. International trial registries are aggregated by the WHO ICTRP.

Frequently Asked Questions

What is the NCT05940324 clinical trial studying?

The purpose of this study is to understand how ketamine works in the brain to bring about a reduction in OCD symptoms. The full protocol is registered on ClinicalTrials.gov and includes the primary outcome measures, eligibility criteria, and study endpoints.

Who can participate in NCT05940324?

Eligibility for this trial depends on the specific inclusion and exclusion criteria set by the sponsor. The plain-English summary above translates the most important criteria into accessible language; the official clinical text is preserved in the collapsible section underneath. Whether you fit any specific trial is a medical decision your doctor needs to confirm — bring the trial information to your treating physician for a full review against your medical history.

How do I contact the trial site for NCT05940324?

Contact information registered with ClinicalTrials.gov is shown in the sidebar of this page. Before reaching out, confirm with your treating physician that this trial is appropriate for your situation. The trial site will then walk you through the screening process to determine final eligibility.

Is participating in a clinical trial safe?

Clinical trials in the United States are regulated by the FDA and overseen by Institutional Review Boards (IRBs) that review the protocol for safety. Risk varies by trial — Phase 1 studies test new treatments in humans for the first time, while Phase 3 trials use treatments that have already passed earlier safety screening. The informed consent document for any specific trial details the known risks and what to expect. Discuss those risks with your physician before deciding whether to participate.

Where can I verify the data on this page?

Every detail on this page comes directly from the ClinicalTrials.gov API. Click "View on ClinicalTrials.gov" in the sidebar to see the official, unmodified record. The federal record is always authoritative; this page is a structured presentation with a plain-English eligibility translation. For background on how clinical trials are regulated, see the FDA drug approval process documentation.

How This Page Is Built

Every field on this page is pulled directly from the ClinicalTrials.gov API v2 — no estimates, no proxies. The plain-English eligibility translation is generated from the original protocol text and reviewed for fidelity to the underlying clinical criteria. The original clinical text remains visible in the collapsible section above so users and clinicians can verify the translation. Read the full methodology for the data pipeline and known limitations.

Source: ClinicalTrials.gov API v2 record for NCT05940324. Maintained by the National Library of Medicine at NIH. Public domain. Cite as: "TrialFinderData. NCT05940324. Data: ClinicalTrials.gov."

Medical disclaimer: This page is informational, not medical advice. Talk to your doctor about whether a clinical trial is right for you.

Last updated 2026-05-08 · Data from ClinicalTrials.gov.