Skip to content
Clinical Trials – home

Rare diseases

Investigational molecules

Locations

Our offerNewsroom

Recruiting

Study of Rituximab for Patients with Psychosis or Obsessive-Compulsive Disorder Linked to Immune System Involvement

Verified siteRegistered drug
Clinical Trials Concierge

Prefer not to search? Our Concierge searches the trials for you.

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 medication called Rituximab on patients who have either Psychosis or Obsessive-Compulsive Disorder (OCD). These conditions are being studied in patients where there is an indication that the immune system might be involved. Rituximab is a treatment that is being compared to a placebo to see if it is effective for this specific group of patients.

The purpose of the study is to evaluate whether Rituximab can be a clinically effective treatment for patients with these conditions. During the study, participants will receive either Rituximab or a placebo. The study will monitor changes in symptoms over time to determine the effectiveness of the treatment. Participants will be observed for improvements in their psychiatric and neurological symptoms, as well as any changes in their overall health and well-being.

The study will last for several months, with regular check-ups to assess the participants' progress. The safety of Rituximab will also be closely monitored throughout the trial. This research aims to provide valuable insights into whether Rituximab can help patients with Psychosis or OCD when the immune system is involved, potentially leading to better treatment options in the future.

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

    Upon joining the study, an initial assessment is conducted to confirm eligibility. This includes reviewing medical history and current medications.

    Eligibility is based on specific criteria, such as age between 18 and 55, a diagnosis of certain psychiatric conditions, and previous treatment history.

  2. Step 2

    Baseline evaluation

    A baseline evaluation is performed to assess the current state of psychiatric symptoms. This involves using various psychiatric rating scales.

    Blood samples and other tests may be conducted to gather initial data.

  3. Step 3

    Treatment phase

    The treatment phase involves receiving either Rituximab or a placebo through an infusion. The specific schedule and dosage are determined by the study protocol.

    The primary goal is to evaluate the effectiveness of Rituximab in treating symptoms related to psychosis or obsessive-compulsive disorder with immune system involvement.

  4. Step 4

    Main evaluation

    After eight months, a main evaluation is conducted to measure changes in psychiatric symptoms using the same scales as the baseline evaluation.

    The results are compared between those who received Rituximab and those who received the placebo.

  5. Step 5

    Follow-up assessments

    Follow-up assessments occur every four months up to 16 months. These include psychiatric evaluations, blood tests, and neurological exams.

    The aim is to monitor the longevity of any improvements and assess the safety of the treatment.

  6. Step 6

    Final assessment

    A final assessment is conducted at the end of the study period to gather comprehensive data on the treatment's long-term effects.

    This includes a thorough review of all collected data and any adverse events experienced during the trial.

Who can join the trial?

12 criteria

  • The patient must have a diagnosis of either Obsessive-Compulsive Disorder (OCD), Obsessive-Compulsive Behavior (OCB), or a type of psychotic disorder such as schizophrenia or delusional disorder.
  • The patient's condition should show signs of active inflammation, and the time since the disease or episode started should be no more than 10 years.
  • The patient should have experienced an acute or unusual start of symptoms, or episodes with symptoms like confusion, hallucinations, or changes in personality.
  • The patient should have at least one of the following: a history of infection, improvement with anti-inflammatory treatments, evidence of brain inflammation on scans, abnormal brain activity, or signs of inflammation or autoimmunity in blood or spinal fluid tests.
  • The patient should be between the ages of 18 and 55.
  • The patient should have a minimum score of "Moderately ill" on a clinical severity scale.
  • The patient should be able to speak Swedish or English.
  • The patient should have tried at least two standard psychiatric medications at the highest tolerable dose for six months without significant improvement.
  • The patient's medication should not have changed for at least one month before starting the study.
  • The patient must sign a consent form agreeing to participate in the study.
  • The patient must use effective birth control methods.
  • The patient should not have evidence of brain shrinkage or scarring on scans.

Who cannot join the trial?

11 criteria

  • Patients who have a history of severe allergic reactions to medications.
  • Individuals with active infections that require treatment.
  • Patients who are currently receiving treatment with other medications that affect the immune system.
  • Individuals with a history of cancer within the last five years.
  • Patients who are pregnant or breastfeeding.
  • Individuals with severe heart disease.
  • Patients with uncontrolled high blood pressure.
  • Individuals with severe liver or kidney disease.
  • Patients who have participated in another clinical trial within the last 30 days.
  • Individuals with a history of drug or alcohol abuse within the last year.
  • Patients who are unable to comply with the study procedures.
Clinical Trials Concierge

Prefer not to search? Our Concierge searches the trials for you.

Tell us about your condition – we search every trial in Europe and connect you with the right site.

We usually reply within a few days

Verified sites

All sites with verified contact details – recruitment status may not be available; ask directly

Trial locations

Where you can join this trial

Countries are shaded by recruitment status. Click a recruiting country to ask about joining there.

Recruiting
Not finding your country?

Not sure what to do next?

Joining a clinical trial can seem overwhelming. We guide you step by step, so you know exactly what to expect and how we support you through the process.

See the full process and FAQ

Investigated drugs

Rituximab is a medication being studied for its potential effectiveness in treating patients with psychosis and/or obsessive-compulsive disorder (OCD) or obsessive-compulsive behavior (OCB) when there is an indication of immune system involvement. It works by targeting specific cells in the immune system, which may help reduce symptoms in these conditions.

What is already known about the treatment

Rituximab – Rituximab is administered through an intravenous infusion, meaning it is delivered directly into the bloodstream via a vein. It is currently being studied in clinical trials for its potential effectiveness in treating psychosis and obsessive-compulsive disorder (OCD) when there is evidence of immune system involvement. The medication is primarily used to target and reduce certain immune cells, specifically B cells, by binding to a protein called CD20 on their surface, leading to their destruction. Rituximab is classified as a monoclonal antibody, which is a type of targeted therapy designed to interact with specific proteins in the body.

Investigated diseases

  • Psychosis

    Psychosis is a mental health condition characterized by a disconnection from reality. Individuals may experience hallucinations, delusions, and disorganized thinking. These symptoms can lead to difficulties in distinguishing what is real from what is not. The condition can develop gradually or suddenly and may vary in intensity. It often affects a person's ability to function in daily life. The progression can be influenced by various factors, including stress and underlying health conditions.

  • Obsessive-Compulsive Disorder (OCD)

    Obsessive-Compulsive Disorder is a mental health disorder where individuals experience persistent, unwanted thoughts (obsessions) and repetitive behaviors (compulsions). These compulsions are often performed in an attempt to reduce the anxiety caused by the obsessions. The disorder can interfere significantly with daily activities and social interactions. Symptoms may fluctuate in severity over time. The condition can develop in childhood or adulthood and often requires long-term management.

Trial detailsLast updated 2 Oct 2026
Age18+ yearsPhasePhase IITrial ID2024-518391-31-00Protocol codeRA-P-OCD-01Estimated enrolment40 patientsSponsorRegion Uppsala

sourced from the EU Clinical Trials Register and site verification

Want to learn more about this trial or check if you can participate?

Clinical Trials Concierge

Prefer not to search? Our Concierge searches the trials for you.

Tell us about your condition – we search every trial in Europe and connect you with the right site.

ClinicalTrials.eu

Every clinical trial in Europe, in plain language.

Explore the full ecosystem of clinical research in Europe.

Search trials

Legal notice · Published by CTIN POLAND sp. z o.o., ul. rtm. Witolda Pileckiego 67/109, 02-781 Warsaw, Poland · KRS 0001111334 · REGON 528919042 · NIP 9512598637

© 2026 Clinical Trials EU – European Clinical Trials Information Network

GDPR compliance, ISO 9001 and ISO 27001 certified (LL-C Certification)

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).