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Updated May 2026 · ClinicalTrials.gov

RECRUITINGPhase 3INTERVENTIONAL

TMS for Exposure Therapy Resistant OCD

Transcranial Magnetic Stimulation (TMS) for Patients With Exposure Therapy-resistant Obsessive-compulsive Disorder (OCD): TETRO - a Multicenter Randomized Controlled Trial

TMS for Exposure Therapy Resistant OCD (NCT05331937) is a Phase 3 interventional studying 1 Hz Real rTMS to the Pre-SMA and 1 Hz Sham rTMS to the Pre-SMA, sponsored by Amsterdam UMC, location VUmc. RECRUITING as of the most recent ClinicalTrials.gov update. Talk to your doctor before contacting the trial site.

Important: This information is not medical advice. Talk to your doctor about whether a clinical trial is right for you.

About This Trial

TETRO is a multi-center placebo-controlled double-blind randomized controlled trial with an intervention phase of 5-7 weeks and a follow-up phase of 12 months in 250 adult (18 years and older) OCD patients who show no/insufficient response to ERP, aiming to establish the cost-effectiveness of low frequency (1 Hz) rTMS to the pre-SMA (compared to sham rTMS to the pre-SMA) as adjuvant treatment to exposure with response prevention (ERP). The treatment consists of 4 times/week rTMS combined with ERP for at least 5 weeks (20 sessions), with optional extension phase of 1 or 2 weeks (maximum of 28 sessions in total).

What Stage of Research Is This?

Phase 3 trials confirm efficacy and safety in large patient groups (often 300–3,000+) and form the evidence base for an FDA approval submission. For 1 Hz Real rTMS to the Pre-SMA, Phase 3 studies typically randomize participants between the investigational treatment and either a placebo or current standard of care. A successful Phase 3 result is the threshold most treatments need to clear before regulatory approval.

This trial is currently recruiting participants. The sponsor has registered the study with ClinicalTrials.gov as actively enrolling, which means new applicants who meet the eligibility criteria can be considered for screening. Trial status can change between updates — confirm current recruiting status with the study contact before traveling for a screening visit.

Target enrollment of 250 participants puts this in the typical range for a Phase 2-style efficacy study or a moderate Phase 3 trial in a focused 1 Hz Real rTMS to the Pre-SMA subpopulation. At this scale, the study has enough statistical power to detect a clear treatment effect but is not the largest cohort in the field.

Who May Be Eligible (Plain English)

Who May Qualify: - OCD as current primary diagnosis - Age 18 and older - Yale-Brown Obsessive-Compulsive Scale (YBOCS) score of 16 or higher. - Insufficient response to state-of-the art exposure therapy with response prevention (ERP) and/or drop-out from ERP due to extreme anxiety/avoidance - The following comorbid disorders are allowed (as long as OCD is the current primary diagnosis): depression, other anxiety disorders, ADHD, tic/Tourette's disorder, eating disorders, personality disorders, autism spectrum disorder (when this does not dominate the clinical profile, i.e. is not main diagnosis). - Commitment to actively undergo intensive exposure therapy (both supervised during ERP sessions, as well as unsupervised at home) - Unmedicated (for at least 8 weeks) or stable dosage of psychotropic medication (for at least 8 weeks), involving serotonergic antidepressants (SSRI, SNRI, clomipramine). Other psychotropic medication that is allowed (provided dosage is stably established for at least 8 weeks): methylphenidate, mood stabilizers, antipsychotic drugs - Ability to participate in frequent treatment sessions (4 days/week, for 5 (or 6, or 7) weeks) at one of the 5 sites nearest to their home and/or work - Ability to participate in pre-treatment MRI session (for neuronavigation) at one of the 3 academic sites nearest to their home and/or work - Capacity for providing willing to sign a consent form Who Should NOT Join This Trial: - OCD patients with hoarding as main symptom dimension - The following comorbid disorders (current diagnosis) are not allowed: psychotic disorders, bipolar disorder, autism spectrum disorder (when this dominates the clinical profile, i.e. is diagnosed as main disorder), substance use disorder - Active suicidal thoughts and intent to act on it - Chronic use of benzodiazepines is not allowed - Cochlear implant - (History of) epilepsy - Pregnancy ...See full criteria on ClinicalTrials.gov Always talk to your doctor about whether this trial is right for you.

These are translations of the protocol\'s inclusion and exclusion criteria, simplified for patients and caregivers. The original clinical text appears below. Eligibility is ultimately confirmed by the trial site\'s screening process — this summary is a starting point for a conversation with your doctor, not a final determination.

Original Eligibility Criteria

View original clinical language
Inclusion Criteria: * OCD as current primary diagnosis * Age 18 and older * Yale-Brown Obsessive-Compulsive Scale (YBOCS) score of 16 or higher. * Insufficient response to state-of-the art exposure therapy with response prevention (ERP) and/or drop-out from ERP due to extreme anxiety/avoidance * The following comorbid disorders are allowed (as long as OCD is the current primary diagnosis): depression, other anxiety disorders, ADHD, tic/Tourette's disorder, eating disorders, personality disorders, autism spectrum disorder (when this does not dominate the clinical profile, i.e. is not main diagnosis). * Commitment to actively undergo intensive exposure therapy (both supervised during ERP sessions, as well as unsupervised at home) * Unmedicated (for at least 8 weeks) or stable dosage of psychotropic medication (for at least 8 weeks), involving serotonergic antidepressants (SSRI, SNRI, clomipramine). Other psychotropic medication that is allowed (provided dosage is stably established for at least 8 weeks): methylphenidate, mood stabilizers, antipsychotic drugs * Ability to participate in frequent treatment sessions (4 days/week, for 5 (or 6, or 7) weeks) at one of the 5 sites nearest to their home and/or work * Ability to participate in pre-treatment MRI session (for neuronavigation) at one of the 3 academic sites nearest to their home and/or work * Capacity for providing informed consent Exclusion Criteria: * OCD patients with hoarding as main symptom dimension * The following comorbid disorders (current diagnosis) are not allowed: psychotic disorders, bipolar disorder, autism spectrum disorder (when this dominates the clinical profile, i.e. is diagnosed as main disorder), substance use disorder * Active suicidal thoughts and intent to act on it * Chronic use of benzodiazepines is not allowed * Cochlear implant * (History of) epilepsy * Pregnancy * Extreme claustrophobia or metallic objects in or on the body, preventing from participation in MRI session * Space-occupying lesion on MRI * Previous rTMS treatment (for blinding reasons)

Treatments Being Tested

COMBINATION_PRODUCT

repetitive transcranial magnetic stimulation (rTMS)

rTMS (real versus sham) is used as adjuvant to ERP

Locations (8)

Trial sites listed on ClinicalTrials.gov for this study. Site activation status can vary — confirm with the specific site before traveling for a screening visit.

Amsterdam UMC, location VU Medical Center
Amsterdam, North Holland, Netherlands
GGZ inGeest
Amsterdam, Netherlands
Neurocare
Eindhoven, Netherlands
Neurocare
Groningen, Netherlands
Maastricht UMC+
Maastricht, Netherlands
Mondriaan
Maastricht, Netherlands
ProPersona
Nijmegen, Netherlands
Radboudumc
Nijmegen, Netherlands

How to Talk to Your Doctor About This Trial

Bring the printable summary of this trial — including the NCT ID (NCT05331937), the sponsor (Amsterdam UMC, location VUmc), and the key eligibility criteria — to your next appointment. Your doctor can review the inclusion and exclusion criteria against your medical history, lab values, and current treatments to assess whether you are likely to qualify. They can also help you weigh whether trial participation makes sense alongside your existing care plan.

Useful questions to walk through together: What does the trial protocol require beyond standard care? How long is the active treatment phase, and how long is follow-up? Are there study visits at sites I can reach? Who pays for the trial-specific procedures, and who pays for standard-of-care portions? See our 25 questions to ask about clinical trials guide for a more complete checklist.

Authoritative Sources

The official record for this trial lives on ClinicalTrials.gov — the federal registry maintained by the National Library of Medicine at NIH. For background on how this trial fits into the FDA approval pathway, see the FDA drug approval process. For oncology-specific guidance for patients considering trials, the National Cancer Institute publishes patient-oriented overviews. International trial registries are aggregated by the WHO ICTRP.

Frequently Asked Questions

What is the NCT05331937 clinical trial studying?

TETRO is a multi-center placebo-controlled double-blind randomized controlled trial with an intervention phase of 5-7 weeks and a follow-up phase of 12 months in 250 adult (18 years and older) OCD patients who show no/insufficient response to ERP, aiming to establish the cost-effectiveness of low frequency (1 Hz) rTMS to the pre-SMA (compared to sham rTMS to the pre-SMA) as adjuvant treatment to exposure with response prevention (ERP). The treatment consists of 4 times/week rTMS combined with ERP for at least 5 weeks (20 sessions), with optional extension phase of 1 or 2 weeks (maximum of 28 s… The full protocol is registered on ClinicalTrials.gov and includes the primary outcome measures, eligibility criteria, and study endpoints.

Who can participate in NCT05331937?

Eligibility for this trial depends on the specific inclusion and exclusion criteria set by the sponsor. The plain-English summary above translates the most important criteria into accessible language; the official clinical text is preserved in the collapsible section underneath. Whether you fit any specific trial is a medical decision your doctor needs to confirm — bring the trial information to your treating physician for a full review against your medical history.

How do I contact the trial site for NCT05331937?

Contact information registered with ClinicalTrials.gov is shown in the sidebar of this page. Before reaching out, confirm with your treating physician that this trial is appropriate for your situation. The trial site will then walk you through the screening process to determine final eligibility.

Is participating in a clinical trial safe?

Clinical trials in the United States are regulated by the FDA and overseen by Institutional Review Boards (IRBs) that review the protocol for safety. Risk varies by trial — Phase 1 studies test new treatments in humans for the first time, while Phase 3 trials use treatments that have already passed earlier safety screening. The informed consent document for any specific trial details the known risks and what to expect. Discuss those risks with your physician before deciding whether to participate.

Where can I verify the data on this page?

Every detail on this page comes directly from the ClinicalTrials.gov API. Click "View on ClinicalTrials.gov" in the sidebar to see the official, unmodified record. The federal record is always authoritative; this page is a structured presentation with a plain-English eligibility translation. For background on how clinical trials are regulated, see the FDA drug approval process documentation.

How This Page Is Built

Every field on this page is pulled directly from the ClinicalTrials.gov API v2 — no estimates, no proxies. The plain-English eligibility translation is generated from the original protocol text and reviewed for fidelity to the underlying clinical criteria. The original clinical text remains visible in the collapsible section above so users and clinicians can verify the translation. Read the full methodology for the data pipeline and known limitations.

Source: ClinicalTrials.gov API v2 record for NCT05331937. Maintained by the National Library of Medicine at NIH. Public domain. Cite as: "TrialFinderData. NCT05331937. Data: ClinicalTrials.gov."

Medical disclaimer: This page is informational, not medical advice. Talk to your doctor about whether a clinical trial is right for you.

Last updated 2026-05-08 · Data from ClinicalTrials.gov.