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Taking people in NorwayPhase 2

Ketamine as ongoing treatment for hard-to-treat depression

Tests ongoing ketamine treatment in adults with hard-to-treat depression.

Key facts

Who runs it
Ostfold Hospital Trust
Where
Bergen, Brumunddal, Graalum, Kristiansand S, Loerenskog, Oslo, Stavanger, Toensberg, Tromsoe, and Trondheim, NorwaySee the 10 sites
Registry title
Ketamine maintenance treatment for depression: A multicenter open-label randomized controlled trial (PreKET)
Status
Recruiting
Phase
Phase 2
People taking part
230 people, planned
Started
9 Oct 2026
Expected to end
31 Dec 2033
Type of study
Interventional
Record updated
18 September 2026

Who can take part

AI summary

From the trial's eligibility criteria. Machine-read from the registry text on this page, so it can be wrong. The registry text below and the trial team decide who can take part.

The trial is looking for adults with treatment-resistant depression who had ketamine induction treatment. It tests long-term ketamine infusions given as maintenance treatment.

Age
18 years or older
Sex
Women and men can join.
Disease stage
Major depression or bipolar-2 disorder, with a current depressive episode of at least moderate severity (MADRS score of 20 or more). Depression must be treatment-resistant: at least two earlier treatments without adequate response.
Earlier treatment
At least two earlier evidence-based treatments for depression (medicines, psychotherapy, ECT or TMS) without adequate response. No ketamine treatment in the 6 months before joining. No ECT or TMS within four weeks before joining or during the trial.

Main reasons for not taking part

  • Pregnant, planning pregnancy or breast-feeding
  • Earlier or current manic episodes, psychotic disorder or bipolar type 1 disorder
  • Acute suicide risk, or severe alcohol or drug use disorder
  • Serious heart, liver or kidney disease, or recent stroke or heart attack
  • BMI under 16 or over 35, or body weight over 150 kg (331 lb)

The registry criteria, word for word

Show all 29 criteriaShow less

Who can take part

  • ● 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 urine and/or blood hCG 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

Who cannot take part

  • ● Obstructive or central sleep apnoea requiring treatment with oxygen, CPAP/BiPAP
  • ● Previous anaphylactic reaction to ketamine
  • ● 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
  • ● Chronic respiratory failure (requiring LTOT and/or GOLD 3 (severe) or higher)
  • ● 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
  • 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)
  • ● Women who intend to become pregnant or are breast-feeding
  • ● Pregnant women as assessed by urine and/or blood hCG pregnancy tests
  • ● Glaucoma or globe injury
  • ● Uncontrolled hypo- or hyperthyroidism
  • ● Current or suspected increased intracranial pressure
  • ● Acute intermittent porphyria
  • ● 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

Where in Norway

  • Helse Bergen HFBergen, NorwayTaking people
  • Sykehuset Innlandet HFBrumunddal, NorwayTaking people
  • Sykehuset Ostfold HFGraalum, NorwayTaking people
  • Sorlandet Sykehus HFKristiansand S, NorwayTaking people
  • Akershus University HospitalLoerenskog, NorwayTaking people
  • Oslo University Hospital HFOslo, NorwayTaking people
  • Helse Stavanger HFStavanger, NorwayTaking people
  • Sykehuset I Vestfold HFToensberg, NorwayTaking people
  • Universitetssykehuset Nord-Norge HFTromsoe, NorwayTaking people
  • St. Olavs hospital HFTrondheim, NorwayTaking people

About the trial

What the trial wants to find out

To examine the long-term efficacy of maintenance therapy with IV ketamine following induction treatment of treatment-resistant depression (TRD).

Questions to ask the study team

  1. How often do I need to come in, and for how long each time?
  2. Are travel costs paid?
  3. Can I keep my own doctor?
  4. What happens if I want to stop?

Contact the study team: see the registry record

Print a page for my doctor

Data and sources

Registry record
Listed on the EU's official list of trials (CTIS).
Official title
Ketamine maintenance treatment for depression: A multicenter open-label randomized controlled trial
Plain-language title
Ketamine as ongoing treatment for hard-to-treat depressionGenerated from the registry record. The registry title is the official one.
AI summary
From the trial's eligibility criteria. Read by machine on 9 November 2026.
Record updated
18 September 2026