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A study on ketamine maintenance treatment for patients with treatment-resistant major depression disorder

Verified siteRegistered drugNo placebo
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What is this trial about?

A plain-language summary of the goals, design and what participants do

This study is looking at Major Depression Disorder, which is a condition where people experience persistent feelings of sadness, loss of interest in activities, and other symptoms that affect daily life. The study focuses specifically on treatment-resistant depression, which means depression that has not improved enough with at least two different types of treatments such as medications, talking therapy, or brain stimulation treatments. The medication being tested in this study is ketamine hydrochloride, which will be given through an infusion, meaning it will be delivered directly into a vein over a period of time. The study will also include people who have bipolar-2 disorder, which is a condition involving mood changes between depression and less severe elevated moods.

The purpose of this study is to examine how well long-term maintenance treatment with ketamine works for keeping depression symptoms from coming back after an initial treatment period. The study is designed to compare different treatment approaches over time to see which one is most effective at preventing depression from returning. Participants will be divided into three different treatment groups to compare the results. The study will look at how long it takes for depression symptoms to come back after the initial treatment phase and after the last ketamine infusion, using a depression rating scale to measure symptom severity.

During the study, participants will receive ketamine infusions according to their assigned treatment group, with the treatment lasting up to 10 days in total. The maximum daily dose will be 150 milligrams, and the maximum total dose across all infusions will be 2700 milligrams. Throughout the study, doctors will monitor participants for any unwanted effects or reactions to the treatment through interviews, observations, questionnaires, and review of medical records. Women who could become pregnant must have a negative pregnancy test before starting the study and before each maintenance ketamine infusion, and must use highly effective birth control methods throughout their participation in the study.

The research process

The trial runs in 6 steps – from screening to follow-up. Each step says what happens and what the team monitors.

  1. Step 1

    Initial assessment and entry into the study

    Upon entering the study, your eligibility will be confirmed. This includes verification that you are 18 years of age or older and that you have been diagnosed with Major Depression Disorder or bipolar-2 disorder.

    Your depression severity will be assessed using the Montgomery-Åsberg Depression Rating Scale, which is a questionnaire that measures depression symptoms. A score of 20 or higher is required, indicating at least moderate depression.

    It will be confirmed that you have previously tried at least two different treatments for depression, such as medications, therapy, or brain stimulation treatments, without sufficient improvement.

    If you are a woman who could become pregnant, a pregnancy test will be performed before starting treatment. You will need to use highly effective birth control methods throughout the treatment period.

  2. Step 2

    Induction phase with ketamine treatment

    You will receive ketamine hydrochloride administered through infusion, which means the medication will be given directly into a vein over a period of time.

    This initial treatment phase is designed to help reduce your depression symptoms.

    During each infusion, you will be monitored for any side effects or reactions to the medication.

  3. Step 3

    Assignment to maintenance treatment group

    After the induction phase, you will be randomly assigned to one of three treatment groups for the maintenance phase.

    The maintenance phase is designed to determine which approach is most effective at preventing depression symptoms from returning.

  4. Step 4

    Maintenance phase

    Depending on the group you are assigned to, you may continue to receive ketamine hydrochloride infusions at scheduled intervals, or you may receive a different maintenance treatment approach.

    If you continue with ketamine infusions, each dose will be given through infusion into a vein.

    If you are a woman who could become pregnant, a pregnancy test will be performed before each ketamine infusion during this phase.

    The maintenance phase will continue for an extended period to assess how well the treatment prevents your depression from worsening or returning.

  5. Step 5

    Regular monitoring and assessments

    Throughout the study, your depression symptoms will be regularly assessed using the Montgomery-Åsberg Depression Rating Scale.

    You will be monitored for any side effects or adverse reactions through clinical interviews, observation, questionnaires, and review of your medical records.

    Any side effects you experience will be documented, including their frequency, severity, and how long they last.

    You should report any symptoms or concerns that arise during the study period.

  6. Step 6

    Final visit

    After completing the maintenance phase, you will have a final study visit.

    A comprehensive assessment will be conducted to evaluate your overall response to the treatment.

    Any remaining side effects or concerns will be addressed during this visit.

Who can join the trial?

7 criteria

  • You must be able to speak and read Norwegian fluently
  • You must be able to give your informed consent, which means you understand the study and agree to take part in it voluntarily
  • You must be an adult aged 18 years or older
  • You must have been diagnosed with Major Depression Disorder, which is a serious form of depression, or bipolar-2 disorder, which is a condition with episodes of depression and periods of elevated mood
  • You must currently be experiencing a major depressive episode, which means a period of low mood and other symptoms of depression, that is at least moderate in severity with a score of 20 or more on a depression rating scale
  • You must have treatment-resistant depression, which means your depression has not improved enough after trying at least two different proven treatments such as medications, therapy sessions, or brain stimulation treatments
  • If you are a woman who could become pregnant, you must have a negative pregnancy test before starting the study and before each treatment, and you must agree to use highly effective birth control methods throughout the treatment period

Who cannot join the trial?

3 criteria

  • The study does not provide specific exclusion criteria in the available information, which means the detailed reasons why someone cannot participate are not listed in the source data provided.
  • Generally, for studies involving ketamine, which is a medication given through a vein to treat severe depression, there may be standard restrictions, but these specific details are not included in the current documentation.
  • If you are interested in this study for treatment-resistant depression, which means depression that has not improved with usual treatments, you would need to speak with the research team to learn about any specific conditions or situations that would prevent participation.
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Investigated drugs

Ketamine is a medication that will be given through an intravenous (IV) line, which means it will be delivered directly into a vein. In this trial, ketamine is being studied as a maintenance treatment for people with treatment-resistant depression, which means depression that has not improved with other treatments. The medication will be used to help maintain the improvements achieved during an initial treatment phase and to see if it can help prevent depression symptoms from returning over a longer period of time.

What is already known about the treatment

Ketamine – Ketamine is a medication given through an intravenous (IV) infusion directly into a vein, which is being studied as a maintenance treatment for people with major depression disorder who have not responded well to other antidepressants, a condition called treatment-resistant depression. This drug works by blocking certain receptors in the brain called NMDA receptors, which helps to rapidly increase the connections between brain cells and improve mood regulation. Ketamine belongs to a class of medications known as NMDA receptor antagonists and anesthetics, and while it has been used for decades as an anesthetic during surgery, its use for depression treatment is a newer application currently being researched in clinical trials. The goal of this study is to determine if regular ketamine infusions can help maintain improvement in depression symptoms over a longer period of time after an initial treatment phase.

Investigated diseases

Major Depressive Disorder – Major Depressive Disorder is a mental health condition characterized by persistent feelings of sadness, emptiness, or loss of interest in activities that were once enjoyable. People with this disorder experience these symptoms for most of the day, nearly every day, for at least two weeks. The condition affects how a person thinks, feels, and handles daily activities such as sleeping, eating, or working. Symptoms may include changes in appetite, difficulty sleeping or sleeping too much, loss of energy, and difficulty concentrating. The disorder can vary in severity and may occur as a single episode or recur multiple times throughout a person's life. Treatment-resistant depression refers to cases where the condition does not respond adequately to standard treatment approaches.
Trial detailsLast updated 7 Oct 2026
Age18+ yearsPhasePhase IITrial ID2025-521330-29-00Protocol codePreKETEstimated enrolment230 patientsSponsorOstfold Hospital Trust

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