Sign in

NCT06668571RecruitingPhase 2

Intravenous Ketamine for Treatment-Resistant Depression

Central and Peripheral GABA and Glutamate Modulation With Intravenous Ketamine for Treatment-Resistant Depression (G2K): A Randomized, Double-Blind, Placebo-Controlled Study

Source: ClinicalTrials.gov · Last updated 16 Oct 2026

Brief summary (registry, in English)

The purpose of this study is to to evaluate the relationships between peak (% change from baseline) central GABA and Glu levels during a 40-min IV ketamine or normal saline infusion utilizing fMRS, and change in peripheral GABA and Glu levels from baseline to 24-hr postinfusion utilizing LCMS, with baseline to 24-hr post-infusion change in depression (MADRS) in 30 TRD adults.

Status (registry)
Recruiting
Phase (registry)
Phase 2
Study type
Interventional
Enrollment
30 (estimated)
First submitted
16 Oct 2024
Start date
10 Feb 2025
Primary completion date
31 Dec 2027
Lead sponsor
Mayo Clinic
Diseases
Depression
NCT number
NCT06668571

What you commit to

  • Study type: Interventional · Phase 2
  • Planned participants: 30
  • From 10 Feb 2025 to the primary completion date, 31 Dec 2027
  • 1 site in 1 country
  • Visits and tests: ask the trial team, the registry does not list them

Built from the registry fields of ClinicalTrials.gov. It describes the study, not your situation.

Who cannot take part

Copied verbatim from ClinicalTrials.gov and grouped by topic. Only the trial team decides who can take part.

Prior treatment

  • Medications known to affect glutamate (i.e., Riluzole, Carbamazepine) or GABA (zaleplon, zolpidem, zopiclone, Valproate, Gabapentin, Pregabalin, tiagabine, and vigabatrin) are prohibited within two weeks prior to administration of study drug and at least 24 hours after last dose of study drug
  • Monoamine Oxidase Inhibitors (MAOIs) are prohibited two weeks prior to administration of study drug
  • Opioid antagonists (naltrexone, naloxone, nalmefene, methylnaltrexone, buprenorphine and naloxone combination) are prohibited within two weeks prior to administration of study drug and at least 24 hours after last dose of study drug
  • CYP3A4 inducers carbamazepine and modafinil are prohibited within two weeks prior to administration of study drug and at least 24 hours after last dose of study drug.
  • Use of methamphetamine, cocaine, or cannabis. Abuse of stimulant (s) within the prior 12 months
  • Clinical or self-reported diagnosis of delirium, encephalopathy, or related clinical diagnosis within the prior 12 months
  • Received ketamine treatment for depression within the prior 2 months
  • History of either poor antidepressive response to or poor tolerability of ketamine (any route of administration) when previously administered

Other illness

  • Personality disorder being the primary diagnosis
  • Diagnosis of schizophrenia, schizoaffective disorder, bipolar disorder, or active psychotic symptoms
  • Active post-traumatic stress disorder symptoms based on clinical assessment
  • Any active or unstable medical condition judged by the study psychiatrist as conferring too great a level of medical risk to allow inclusion in the study
  • A history of bleeding in the brain
  • Arteriovenous malformation or a history of aneurysm
  • Any current substance use disorder (excluding nicotine and caffeine). Note: Persons will be allowed to enroll in this study if their substance use is in complete (not partial) and sustained (\> 1 year) remission
  • History of traumatic brain injury that resulted in loss of consciousness with brain bleeding
  • History of tonic-clonic (grand mal) seizures
  • Developmental delay, intellectual disability, or intellectual disorder
  • Minor or Major Neurocognitive disorder
  • History of hypothyroidism unless taking a stable dose of thyroid medication and asymptomatic for 3 months
  • Gastroesophageal reflux disease that is poorly managed
  • A diagnosis of Complex Regional Pain Syndrome (CRPS)
  • History of claustrophobia with active symptoms that would interfere with the MRI
  • Poorly controlled hypertension.

Lab values

  • Hepatic insufficiency (2.5 X ULN for AST or ALT) within 3 months of consent, past liver transplant recipient, and/or clinical diagnosis of cirrhosis of the liver

Other

  • Inability to speak English
  • Inability to provide consent or have a legal guardian
  • Patients with a BMI \> 40 kg/m2.
  • Ongoing prescription of \> 2 mg lorazepam equivalents (total) daily, or morning dosing of any benzodiazepine at the time of assessment
  • Currently undergoing TMS, vagal nerve stimulation, or deep brain stimulation as either an acute or maintenance treatment of depression
  • ECT in the past 6 months
  • Pregnancy, or nursing
  • Any contraindication to MRI safety questionnaire

Who the study is looking for

  • Ability to provide informed consent
  • Meets diagnostic criteria for major depressive disorder without psychotic features per the SCID DSM-IV-TR
  • PHQ-9 total score ≥ 15 at screening
  • Treatment-resistant depression, as defined by failure of at least two previous antidepressant treatments within the current depressive episode. Failed antidepressant treatments can include pharmacotherapy for depression at an adequate dose for at least 8 weeks, trial of transcranial magnetic stimulation (TMS) or an acute series of at least 6 administrations of electroconvulsive therapy (ECT)
  • Ability to pass a comprehension assessment test related to effects of ketamine and trial objectives and criteria

Age in the registry: 18 years to 65 years · Sex: All · Does not accept healthy volunteers

Full criteria on ClinicalTrials.gov

Sites (1)

Sites in registry order. Save your city in your profile to sort them by distance.

SiteCityCountrySite status
Mayo Clinic in Rochester
Coordinator of this site? Confirm its status
RochesterUnited StatesRecruiting

This page is information, not medical advice. Discuss any trial with your doctor.