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Study on the Early Effects of Ketamine and Venlafaxine for Hospitalized Patients with Severe Major Depression

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What is this trial about?

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

This clinical trial is focused on studying the effects of a treatment for people experiencing severe episodes of major depressive disorder. The study involves the use of a medication called ketamine, which is being compared to a placebo. The treatment is given in addition to another medication called venlafaxine, which is commonly used to treat depression. The main goal of the study is to see how effective ketamine is in improving depressive symptoms after seven days of treatment.

Participants in the study will receive either ketamine or a placebo, along with venlafaxine, while they are hospitalized for their depressive episode. The study will also use a special imaging technique called PET-MRI to look at changes in the brain before and after the treatment. This will help researchers understand if improvements in depression symptoms are linked to changes in the brain. The study will last for a short period, with the main focus on the first two weeks of treatment.

In addition to monitoring changes in depression symptoms, the study will also look at other factors such as the length of hospital stay and any side effects that may occur. The safety of ketamine will be closely monitored, especially during and shortly after its administration. This research aims to provide more information on how ketamine can be used effectively and safely as part of a treatment plan for severe depression.

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

    Introduction to the trial

    Upon joining the study, the patient will be informed about the trial's purpose, which is to compare the early effects of ketamine with a placebo when added to venlafaxine for treating severe depressive episodes.

    The patient will be required to provide informed consent and confirm eligibility, including age between 18 and 65, and a diagnosis of major depressive disorder with a severe episode.

  2. Step 2

    Initial assessment

    The patient will undergo an initial assessment, including a Hamilton Depression Rating Scale (HDRS) evaluation to establish a baseline score.

    Additional assessments may include the Beck Depression Inventory (BDI) and the Clinical Global Impression (CGI) scale.

  3. Step 3

    Treatment phase

    The patient will receive venlafaxine orally as part of their treatment regimen.

    In addition, the patient will be randomly assigned to receive either ketamine or a placebo through intravenous administration.

    The treatment will be administered over a period of 7 days, with the primary goal of observing changes in depressive symptoms.

  4. Step 4

    Monitoring and evaluation

    Throughout the treatment phase, the patient will be monitored for any side effects, including changes in blood pressure, heart rate, and other potential adverse effects.

    The patient will also undergo a PET-MRI scan before and after the treatment to assess changes in brain activity.

  5. Step 5

    Follow-up assessments

    After the 7-day treatment period, the patient will have follow-up assessments to measure changes in the HDRS score and other scales.

    The length of the hospital stay will be recorded, and any further treatment needs will be evaluated by the clinician.

  6. Step 6

    Completion of the trial

    The trial will conclude with a final assessment of the patient's condition and any long-term effects of the treatment.

    The patient will be informed of the study's findings and any implications for their ongoing care.

Who can join the trial?

8 criteria

  • The patient must have a current major depressive episode as part of Major Depressive Disorder, according to DSM-5 criteria. This means they are experiencing a severe period of depression.
  • The patient must be hospitalized for this episode, which means they are receiving care in a hospital setting.
  • The patient must have a minimum HDRS score of 24. HDRS stands for Hamilton Depression Rating Scale, which is a questionnaire used to measure the severity of depression.
  • The patient must be in a situation where starting treatment with venlafaxine is recommended. Venlafaxine is a medication used to treat depression.
  • The patient must be aged between 18 and 65 years old.
  • The patient must have signed a free and informed consent, meaning they agree to participate in the study after being fully informed about it.
  • The patient must be a member of a social security scheme, which is a system that provides financial support for healthcare.
  • For women who can have children, they must use effective contraception throughout the study to prevent pregnancy.

Who cannot join the trial?

5 criteria

  • Patients who do not have a severe major depressive episode cannot participate. This means the study is only for those currently experiencing a very intense period of depression.
  • Patients who are not taking venlafaxine cannot participate. Venlafaxine is a medication used to treat depression.
  • Patients who are not hospitalized for their severe major depressive episode cannot participate. This means the study is for those who are currently in a hospital due to their depression.
  • Patients who are under 18 years old cannot participate. The study is only for adults.
  • Patients who are part of a vulnerable population cannot participate. This refers to groups of people who might need special protection or care.
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Investigated drugs

  • Ketamine

    is being studied for its potential to quickly reduce symptoms of severe depression. In this trial, it is given intravenously to patients who are already taking another antidepressant. Researchers are interested in seeing if adding ketamine can help improve mood more effectively than a placebo.

  • Venlafaxine

    is an antidepressant that is already being used by patients in this trial. It works by increasing the levels of certain chemicals in the brain that help improve mood. The trial is testing whether adding another treatment to venlafaxine can provide better results for patients with severe depression.

What is already known about the treatment

  • Ketamine

    Ketamine is administered intravenously and is currently being studied for its potential benefits in treating severe major depressive episodes, particularly as an add-on therapy to venlafaxine. It is known for its rapid-acting antidepressant effects, which are being evaluated in clinical trials. The main therapeutic indication for ketamine in this context is major depressive disorder with a current severe episode. At the molecular level, ketamine works by blocking NMDA receptors in the brain, which may lead to increased synaptic connectivity and rapid improvement in depressive symptoms. It is classified pharmacologically as a dissociative anesthetic with antidepressant properties.

  • Venlafaxine

    Venlafaxine is taken orally and is a well-established medication used to treat major depressive disorder. It is part of the standard treatment regimen and is being used in combination with ketamine in clinical trials to assess enhanced efficacy. The main therapeutic indication for venlafaxine is major depressive disorder, and it functions by inhibiting the reuptake of serotonin and norepinephrine, which helps to balance neurotransmitters in the brain and improve mood. Venlafaxine is classified as a serotonin-norepinephrine reuptake inhibitor (SNRI).

Investigated diseases

Major Depressive Disorder with Current Severe Major Depressive Episode – This is a mental health condition characterized by persistent and intense feelings of sadness and despair. Individuals with this disorder experience a severe depressive episode, which significantly impacts their daily functioning. Symptoms may include a profound lack of interest or pleasure in activities, changes in appetite or weight, sleep disturbances, and feelings of worthlessness or excessive guilt. The disorder can also lead to difficulties in concentrating and making decisions. Physical symptoms such as fatigue or a decrease in energy levels are common. The progression of the disorder can vary, with symptoms potentially lasting for weeks or longer if not addressed.
Trial detailsLast updated 2 Oct 2026
Age18+ yearsPhasePhase IIITrial ID2023-506597-12-00Protocol codeAPHP220668Estimated enrolment60 patientsSponsorAssistance Publique Hopitaux De Paris

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On this site, “treatment” means an investigational medicine being studied in a clinical trial. Its safety and efficacy for the use being studied have not yet been confirmed, some participants may receive a placebo or a comparator medicine, and taking part does not guarantee any health benefit. The decision to take part is made by the doctor at the research site. This site is for information only and does not replace medical advice.

This service is not affiliated with the European Commission, the EMA, or the official CTIS system. Most information comes from publicly available international clinical-trial registries, supplemented by data from academic sites, national regulators and commercial sponsors. On this site, “treatment” and “therapy” mean a medicine being tested in a clinical trial. Its safety and effectiveness in the use being studied are not yet confirmed, some participants may receive a placebo or a comparator, and taking part does not guarantee a health benefit. The doctor at the research site decides who can take part. This site provides information, not medical advice. Certain content and visual elements on this website have been generated or enhanced using artificial intelligence (AI).