Obsessive-Compulsive DisorderPhase 2MKET2NCT05940324
Examining Mu Opioid Mechanisms of Ketamine's Rapid Effects in OCD (MKET2)
A Phase 2 study testing Ketamine and Naltrexone Pill in people with Obsessive-Compulsive Disorder, run by Stanford University at 1 site in United States.
Trial summary
The purpose of this study is to understand how ketamine works in the brain to bring about a reduction in OCD symptoms. Read more about this study
- Who is it for?
- Ages 18 to 65 yearsHealthy volunteers can take part
- Conditions the study is for
- Obsessive-Compulsive Disorder
- What is being tested?
- Ketamine and Naltrexone Pill
- Type of treatment
- Pill or oral medicine, Injection or infusion
- Could I receive a placebo?
- Yes, some participants may receive a placebo
- How many people
- 150 participants
- Where
- 1 siteUnited States
- Study dates
- 24 Feb 2024to Nov 2028
- Phase
- Phase 2
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 to 65 years
- All sexes
- Healthy volunteers accepted
- Adult, Older adult
Who may be able to join
- 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
- Ages 18-65
- Able to provide informed consent
Who cannot join
- 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:
- current or past use of psychotropic medication
- pregnant or nursing females
- the presence of metal in the body that is contraindicated for MRI scans
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
United States1 site, 1 recruiting
- Recruiting
Department of Psychiatry & Behavioral Sciences
Stanford, California, 94305
OCD Research, 650-723-4095
About this study
The purpose of this study is to understand how ketamine works in the brain to bring about a reduction in OCD symptoms.
Read the detailed description
The proposed mechanistic trial would be the first to probe the role of ketamine's opioid properties in modulating fronto-striatal circuitry and bringing about reduction of OCD symptoms.
- Conditions
- Obsessive-Compulsive Disorder
- Being tested
- Ketamine, Naltrexone Pill, Placebo pill
- Keywords
- OCD, Ketamine, Naltrexone, MRI, Brain Imaging, OCD symptoms, Obsessive-Compulsive Disorder
- Medical subject headings
- Obsessive-Compulsive Disorder
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
KetamineDrug
Also called Ketamine Hydrochloride, Ketalar
Ketamine is an FDA-approved dissociative anesthetic.
Naltrexone PillDrug
Also called Naltrexone
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)
Placebo pillOther
An oral inactive placebo pill will be administered to preserve the blinded nature of the study.
| Study group | Role | What they receive |
|---|---|---|
| Ketamine + Naltrexone | Experimental | OCD patients in this arm will receive 0.5mg/kg of ketamine - one single infusion. fMRI will be acquired before, during, and after infusion.
Oral naltrexone 50 mg will be administered before the infusion. Receives: Drug: Ketamine; Drug: Naltrexone Pill |
| Ketamine + Placebo | Placebo comparator | OCD patients in this arm will receive 0.5mg/kg of ketamine - one single infusion. fMRI will be acquired before, during, and after infusion.
An oral inactive placebo will be administered before the infusion. Receives: Drug: Ketamine; Other: Placebo pill |
| Healthy Volunteers | No intervention | Healthy volunteers will have one fMRI scan visit. |
What is being measured
The primary outcome is the main question the study is designed to answer.
Change in the severity of OCD symptoms as measured by the Yale-Brown Obsessive Compulsive Scale (YBOCS)
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.
Measured: Baseline (Visit 2) to Post Infusion fMRI scan (Visit 4; Day 1), up to 1 week
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted11 Jul 2023
- Study start24 Feb 2024
- Primary completionNov 2028 (estimated)
- Study completionNov 2028 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Obsessive-Compulsive DisorderStudies of the same condition, open and under way.
- More trials run by Stanford UniversityThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase 2
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Model description
- Participants will be randomized with a 1:1 allocation to either IV ketamine + oral placebo or IV ketamine + oral opioid antagonist naltrexone
- Masking
- Quadruple blind
- Who is masked
- Participant, Care provider, Investigator, Outcomes assessor
- Enrolment
- 150 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Stanford University
- Sponsor type
- University, hospital or other
- Collaborators
- National Institute of Mental Health (NIMH)
- Responsible party
- Principal investigator, Carolyn Rodriguez, Stanford University
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT05940324
- Sponsor's protocol ID
- 70954
- Other IDs
- 1R01MH133553-01
- Acronym
- MKET2
- Status last verified
- Apr 2026
- First submitted
- 3 Jul 2023
- Last updated
- 24 Apr 2026
- Results posted
- No
- Data monitoring committee
- Yes
- FDA-regulated drug
- Yes
- FDA-regulated device
- No
- Individual data sharing
- No
Study at a glance
From the registry record, last updated by the sponsor on 24 Apr 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Examining Mu Opioid Mechanisms of Ketamine's Rapid Effects in OCD (MKET2)
- ClinicalTrials.gov ID
- NCT05940324
- Acronym / sponsor ID
- MKET2 / 70954
- Conditions
- Obsessive-Compulsive Disorder
- Keywords
- OCD, Ketamine, Naltrexone, MRI, Brain Imaging, OCD symptoms, Obsessive-Compulsive Disorder
- Phase
- Phase 2
- Study type
- Interventional
- Recruitment status
- Recruiting
- Enrolment
- 150 participants (estimated)
- Lead sponsor
- Stanford UniversityUniversity, hospital or other
- Collaborators
- National Institute of Mental Health (NIMH)
- Study start
- 24 Feb 2024 (actual)
- Primary completion
- Nov 2028 (estimated)
- Study completion
- Nov 2028 (estimated)
- First posted
- 11 Jul 2023 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
The purpose of this study is to understand how ketamine works in the brain to bring about a reduction in OCD symptoms.
Detailed description
The proposed mechanistic trial would be the first to probe the role of ketamine's opioid properties in modulating fronto-striatal circuitry and bringing about reduction of OCD symptoms.
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Quadruple blind (participant, care provider, investigator, outcomes assessor)
- Number of arms
- 3
- Model description
- Participants will be randomized with a 1:1 allocation to either IV ketamine + oral placebo or IV ketamine + oral opioid antagonist naltrexone
| Arm | Type | Receives |
|---|---|---|
| Ketamine + Naltrexone | Experimental | Drug: Ketamine, Drug: Naltrexone PillOCD patients in this arm will receive 0.5mg/kg of ketamine - one single infusion. fMRI will be acquired before, during, and after infusion. Oral naltrexone 50 mg will be administered before the infusion. |
| Ketamine + Placebo | Placebo comparator | Drug: Ketamine, Other: Placebo pillOCD patients in this arm will receive 0.5mg/kg of ketamine - one single infusion. fMRI will be acquired before, during, and after infusion. An oral inactive placebo will be administered before the infusion. |
| Healthy Volunteers | No intervention | –Healthy volunteers will have one fMRI scan visit. |
Who may qualify
- Ages
- 18 to 65 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (7 listed)
- 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
Key exclusion criteria (8 listed)
- 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
- current or past use of psychotropic medication
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| KetamineAlso: Ketamine Hydrochloride, KetalarKetamine is an FDA-approved dissociative anesthetic. | Drug | Ketamine + Naltrexone, Ketamine + Placebo |
| Naltrexone PillAlso: NaltrexoneNaltrexone 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) | Drug | Ketamine + Naltrexone |
| Placebo pillAn oral inactive placebo pill will be administered to preserve the blinded nature of the study. | Other | Ketamine + Placebo |
Primary outcome
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.
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 24 Apr 2026.
- Individual participant dataSharing planned: No
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Phase 2 study testing Ketamine and Naltrexone Pill in people with Obsessive-Compulsive Disorder, run by Stanford University at 1 site in United States.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 7 inclusion and 8 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: looking for participants now, as of the sponsor's last update on 24 Apr 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in United States. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. Some participants in this study may receive a placebo. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
What does this phase mean?
Phase 2 studies give the treatment to a larger group to see whether it has the intended effect and to keep checking safety.
Not every study follows the same path, and some studies (observational studies, device studies) have no phase.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact Pavithra Mukunda, MS (6504972578, ocdresearch@stanford.edu), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
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). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 24 Apr 2026.