Ongoing Clinical Trials for Obsessive-Compulsive Disorder
There are currently 3 ongoing clinical trials investigating new treatment approaches for obsessive-compulsive disorder. These studies are exploring different medications including ketamine, pramipexole, and rituximab, with trials taking place in Austria, Portugal, and Sweden. Each trial focuses on patients who have not responded well to standard treatments, aiming to find more effective options for managing this challenging condition.
Clinical trial locations
- Austria
- Portugal
- Sweden
Study on Ketamine and Midazolam for Treating Obsessive-Compulsive Disorder in Adults
This trial is being conducted in Austria and focuses on examining how ketamine infusions might help people with obsessive-compulsive disorder. The study uses a cross-over design, meaning participants will receive both ketamine and midazolam at different times to compare their effects.
Who can participate: Adults aged 18 and older with a confirmed diagnosis of OCD as their primary condition can join this study. Participants need to have a Yale-Brown Obsessive-Compulsive Scale score of 16 or higher, which indicates moderate to severe symptoms. Those interested must have tried at least one previous treatment for OCD and be able to provide written informed consent.
Who cannot participate: The study excludes individuals with a history of severe allergic reactions to ketamine, those with uncontrolled high blood pressure, and people with severe heart disease. Patients with severe mental health disorders other than OCD cannot join. Pregnant or breastfeeding women, anyone currently in another clinical trial, and people with a history of substance abuse or addiction are also excluded. Anyone with a significant medical condition that could make participation unsafe will not be eligible.
What the study aims to do: The main goal is to compare how ketamine affects OCD symptoms compared to midazolam. Researchers will monitor participants through several stages, starting with baseline measurements of current symptoms and stress levels using questionnaires and saliva samples to measure cortisol. After each infusion session, participants will be assessed for changes in their symptoms and stress responses. The study also examines how these treatments affect brain functions related to thinking and behavior, particularly under stress.
Investigational drug: Ketamine is administered as a 50 mg/ml solution through an intravenous infusion. It is known for its ability to quickly relieve symptoms of depression and anxiety in some people, and researchers are exploring whether it can similarly help reduce OCD symptoms and improve how the brain functions under stress.
Study on Pramipexole for Patients with Resistant Obsessive-Compulsive Disorder (OCD)
This Portuguese trial is testing whether pramipexole can help people whose OCD has not responded well to standard treatments. The medication is being studied at three different doses to determine if it can enhance the effects of SSRIs, which are commonly prescribed medications for OCD.
Who can participate: Adults between 18 and 64 years old who speak European Portuguese as their first language are eligible. Participants must have a confirmed OCD diagnosis according to DSM-5 or ICD-10 guidelines and a Yale-Brown Obsessive-Compulsive Scale score of 16 or higher. Importantly, participants must have shown resistance to previous treatments, meaning they did not respond adequately to at least two different SSRIs at the highest tolerable dose for at least 12 weeks, and also did not respond to additional treatment with either risperidone or aripiprazole for 6 to 12 weeks. Those capable of having children must use approved birth control methods consistently.
Who cannot participate: Individuals without an OCD diagnosis or those outside the specified age range cannot participate. Vulnerable populations who cannot protect their own interests are excluded. People with other medical conditions that might interfere with the study, those taking medications that could conflict with the study treatment, and pregnant or breastfeeding women are not eligible. Individuals with a history of severe allergic reactions to pramipexole or similar medications, and those unable to comply with study procedures or attend follow-up visits, are also excluded.
What the study aims to do: The trial evaluates whether pramipexole can improve symptoms when added to existing SSRI treatment. After confirming eligibility and recording baseline symptoms, participants receive pramipexole in one of three doses: 0.35 mg, 0.088 mg, or 0.18 mg, or a placebo. Regular monitoring tracks changes in the Yale-Brown Obsessive-Compulsive Scale score and any side effects throughout the study. A final assessment at week 16 measures the difference from baseline to determine treatment effectiveness.
Investigational drug: Pramipexole is taken orally in tablet form. It works by stimulating dopamine receptors in the brain, which may help regulate mood and behavior. The study aims to determine if this medication can enhance the benefits of SSRIs in patients with treatment-resistant OCD.
Study of Rituximab for Patients with Psychosis or Obsessive-Compulsive Disorder Linked to Immune System Involvement
This Swedish trial is investigating rituximab in patients with OCD or psychosis when there are signs that the immune system may be involved in their condition. The study compares rituximab to a placebo to evaluate its effectiveness.
Who can participate: Adults between 18 and 55 years old who speak Swedish or English can join. Participants must have a diagnosis of OCD, obsessive-compulsive behavior, or a psychotic disorder such as schizophrenia or delusional disorder. The condition should show signs of active inflammation, with the disease or episode starting no more than 10 years ago. Participants should have experienced an acute or unusual start of symptoms, or episodes with confusion, hallucinations, or personality changes. They must also have at least one indicator of immune involvement, such as a history of infection, improvement with anti-inflammatory treatments, evidence of brain inflammation on scans, abnormal brain activity, or signs of inflammation in blood or spinal fluid tests. Those interested must have tried at least two standard psychiatric medications at the highest tolerable dose for six months without significant improvement, with no medication changes for at least one month before starting. Participants must score at least “Moderately ill” on a clinical severity scale, sign a consent form, and use effective birth control methods.
Who cannot participate: The study excludes people with a history of severe allergic reactions to medications, active infections requiring treatment, current treatment with other immune-affecting medications, or cancer within the last five years. Pregnant or breastfeeding women, individuals with severe heart disease, uncontrolled high blood pressure, or severe liver or kidney disease cannot participate. Those who have participated in another clinical trial within 30 days, have a history of drug or alcohol abuse within the last year, or are unable to comply with study procedures are also excluded.
What the study aims to do: After initial assessment and baseline evaluation of psychiatric symptoms using rating scales, participants receive either rituximab or placebo through an infusion. The main evaluation occurs at eight months to measure changes in psychiatric symptoms, comparing results between the rituximab and placebo groups. Follow-up assessments continue every four months up to 16 months, including psychiatric evaluations, blood tests, and neurological exams. A final assessment reviews all collected data and any side effects experienced during the trial.
Investigational drug: Rituximab is administered through an intravenous infusion. It works by targeting specific immune cells called B cells by binding to a protein called CD20 on their surface, leading to their destruction. This monoclonal antibody is being studied for its potential to reduce symptoms in OCD and psychosis when the immune system appears to be involved.
Summary
These three trials represent diverse approaches to treating obsessive-compulsive disorder, particularly in patients who have not responded well to standard treatments. The studies are geographically spread across Europe, with one trial in each of Austria, Portugal, and Sweden. Each trial focuses on a different mechanism of action: ketamine targets brain chemistry through NMDA receptor blocking, pramipexole works on dopamine receptors, and rituximab addresses potential immune system involvement. All three studies require participants to have moderate to severe symptoms and previous treatment history, reflecting the focus on finding solutions for treatment-resistant cases. The trials vary in their specific requirements, with the Swedish study uniquely requiring evidence of immune system involvement, while the Portuguese study specifically targets patients who have not responded to multiple previous medication attempts. These ongoing studies may provide valuable information about alternative treatment options for people struggling with OCD.
