This Phase II, multicentre, open-label randomised controlled trial (n=230) will evaluate the long-term efficacy and safety of intravenous ketamine maintenance treatment in adults with treatment-resistant depression (TRD) and a current moderate or severe depressive episode. The primary outcomes are time to relapse after the induction phase and after the final ketamine infusion, assessed using clinician-rated Montgomery–Åsberg Depression Rating Scale (MADRS) scores. Participants will be allocated to monthly ketamine infusions for either 4 or 8 months, or to treatment as usual (TAU) after an initial dose-finding period. Ketamine hydrochloride will be administered by infusion, with a maximum daily dose of 150 mg and maximum total dose of 2700 mg. All participants will be followed for 14 months, with the ketamine groups receiving site-based follow-up after treatment; secondary objectives include assessing the durability of antidepressant effects, safety, and the dose- and duration-related efficacy of ketamine. Shop with Us..
Detailed Description
To examine the long-term efficacy of maintenance therapy with IV ketamine following induction treatment of treatment-resistant depression (TRD).
Study Arms & Interventions
Ketamine 150 mg (8 monthly treatments)
experimental
Monthly ketamine treatments for 8 months, followed by site visits for follow-up purposes for 6 months; a total of 14 months.
Interventions
- Ketamine150 mgvia IV• monthly for 8 months• 8 doses total
Ketamine 150 mg (4 monthly treatments)
experimental
Monthly ketamine treatments for 4 months, followed by site visits for follow-up purposes for 10 months; a total of 14 months.
Interventions
- Ketamine150 mgvia IV• monthly for 4 months• 4 doses total
Treatment as usual
active comparator
Site visits for follow-up purposes for 14 months after the initial dose finding period.
Participants
Ages
18 – ?
Sexes
Male & Female
BMI
–
Psychosis History
–
Inclusion Criteria
- ● Are fluent in spoken and written Norwegian.
- ● Able to provide informed consent to participate in the current study. This may include involuntarily hospitalized patients
- ● Male or female adults aged 18 years or older
- ● Meet DSM-5 criteria for MDD or bipolar-2 disorder as assessed by the MINI version 7.0.2
- ● Have a current MDE of at least moderate severity defined by a Montgomery-Åsberg Depression Rating Scale (MADRS) score of ≥ 20
- ● Meet criteria for treatment-resistant depression, defined by previous treatment for depression included a minimum of two evidence-based treatments (psychopharmacology, psychotherapy, ECT/TMS) without adequate response, in accordance with Canadian Network for Mood and Anxiety Treatments (CANMAT) guidelines for the management of unipolar or bipolar depression
- ● Women of childbearing potential (WOCBP) as defined in Section 10.4.1 must have a negative pregnancy test at study entry and prior to maintenance ketamine infusion and must agree to use adequate birth control through the last ketamine infusion.
- Only highly effective contraception methods are permitted in this trial. See Section 10.6.2 Contraception guidelines for a list of these methods.
Exclusion Criteria
- ● Women who intend to become pregnant or are breast-feeding
- ● Chronic respiratory failure (requiring LTOT and/or GOLD 3 (severe) or higher)
- ● Obstructive or central sleep apnoea requiring treatment with oxygen, CPAP/BiPAP
- ● Pregnant women as assessed by blood HCG tests
- ● Glaucoma or globe injury
- ● Previous anaphylactic reaction to ketamine
- ● Uncontrolled hypo- or hyperthyroidism
- ● Current or suspected increased intracranial pressure
- ● Acute intermittent porphyria
- ● Any other severe medical or neurological condition that, in the investigator’s judgement, may interfere with the interpretation of the study results or pose a health risk to the participant.
- ● Any use of medication deemed by the trial medical professionals to pose a risk when combined with ketamine or likely to interfere with the study results, and that the participant is unwilling or unable to discontinue before enrolment
- ● Ongoing or previous manic episodes
- ● Electroconvulsive therapy (ECT) and transcranial magnetic stimulation (TMS) are not permitted within four weeks prior to enrollment or during the trial.
- ● Ketamine treatment within 6 months preceding enrollment
- ● Not able to provide informed consent to participate in clinical research
- ● BMI under 16 or over 35 or body weight over 150 kg
- ● Outpatients with acute suicide risk as assessed by clinician’s examination
- ● Hospitalized patients with acute suicide risk, unless enrollment doesn’t interfere with clinical security procedures per investigator’s judgement
- ● Ongoing psychotic symptoms unless exclusively explained by the current depressive episode
- ● Ongoing hypomanic episode
- Known hypersensitivity to any ingredients of ketamine
- ● History of any psychotic or bipolar type 1 disorder as assessed by the Mini International Neuropsychiatric Interview (MINI v. 7.0.2)
- ● History of severe personality disorder, severe dissociative disorder, severe obsessive-compulsive disorder, autism-spectrum disorder, or other psyciatric comorbidities, assessed through MINI and/or medical history, that may interfere with the interpretation of the study results or pose a health risk to the participant per investigator’s judgement
- ● Current eating disorder with active purging as assessed by MINI
- ● Current or past severe substance/alcohol use disorder (according to DSM-5 criteria) or substance/alcohol use that, in the investigator’s judgment, may compromise participant safety, study integrity, or compliance with study procedures
- ● Cardiovascular conditions: Heart failure (NYHA class III or IV), recent stroke (< 1 year from enrollment), recent myocardial infarction (< 1 year from enrollment), uncontrolled hypertension (>160/100 mm Hg) or recent clinically significant arrhythmia (< 1 year from enrolment)
- ● Liver failure (Child-Pugh Class C) or impairment of liver function as assessed by medical history, clinical examination and laboratory results at screening (i.e. INR > 1,2 or bilirubin > 30 μmol/L)
- ● Kidney failure (creatinine clearance < 30 mL/min by Cockcroft-Gault)

