Using brain activity markers to predict response to accelerated iTBS for OCD

Investigation of the Relationship Between Electrophysiological Biomarkers and Treatment Response in Patients Diagnosed With Obsessive-Compulsive Disorder Undergoing Transcranial Magnetic Stimulation Therapy

This will try accelerated intermittent Theta Burst Stimulation (iTBS) targeting the dmPFC and ACC to reduce symptoms in adults (18–65) with treatment‑resistant OCD and to find brain activity markers that predict who benefits.

Quick facts

• Phase: NA
• Study type: Interventional
• Enrollment: 30 (estimated)
• Ages: 18 Years to 65 Years
• Sex: All
• Sponsor: Istanbul University - Cerrahpasa (other)
• Locations: 1 site (Istanbul, Bakirkoy)
• Trial ID: NCT07561528 on ClinicalTrials.gov

What this trial studies

This interventional protocol enrolls 30 adults (18–65) with DSM‑5 obsessive‑compulsive disorder who have not responded adequately to at least one SSRI. Participants receive an intensive 7‑day accelerated iTBS program with four sessions per day (28 sessions total) targeted to the dorsomedial prefrontal cortex and anterior cingulate cortex. Clinical symptoms are measured before and after treatment using standardized scales (including Y‑BOCS and Hamilton measures), while EEG microstates and heart rate variability are recorded as candidate electrophysiological biomarkers. Medication doses must be stable for at least two months and common TMS contraindications (for example, seizure risk or metal implants) exclude participation.

Who should consider this trial

Good fit: Adults 18–65 with DSM‑5 OCD, Y‑BOCS ≥20, inadequate response to at least one SSRI, stable medications for two months, and no contraindications to TMS.

Not a fit: People with conditions that increase seizure risk, metal or electronic implants in the head/neck, prior neurosurgery, severe neurodegenerative disease, or those with milder OCD (Y‑BOCS <20) are unlikely to benefit or be eligible.

Why it matters

Potential benefit: If successful, this approach could produce faster symptom reduction for some people with treatment‑resistant OCD and help clinicians identify who is most likely to benefit.

How similar studies have performed: Previous TMS and iTBS studies for OCD have shown mixed but promising results, though accelerated multi‑session protocols and biomarker‑guided selection remain relatively novel.

Eligibility criteria

Inclusion Criteria:

* Being between 18 and 65 years of age.
* Being diagnosed with Obsessive-Compulsive Disorder (OCD) according to DSM-5 criteria.
* Non-responsiveness to at least one Selective Serotonin Reuptake Inhibitor (SSRI) treatment at an adequate dose and duration.
* Having a Y-BOCS score of ≥20 following the initial evaluation.
* No change in the current medications within the last 2 months and a commitment to maintaining stable doses throughout the study.
* Providing informed consent and having no contraindications for TMS.

Exclusion Criteria:

* Severe neurological disorders or neurodegenerative diseases.
* Any condition associated with increased seizure risk
* History of cochlear implants, metal implants in the head and neck area, cardiac pacemakers, deep brain stimulation, or vagus nerve stimulation.
* History of neurosurgical intervention.
* General contraindications for Transcranial Magnetic Stimulation therapy.

Where this trial is running

Istanbul, Bakirkoy

• Cerrahpaşa Tıp Fakültesi Prof. Dr. Murat Dilmener Hastanesi — Istanbul, Bakirkoy, Turkey (Türkiye) (RECRUITING)

Study contacts

• Study coordinator: Sarp Yoldas, MD

Conditions: Obsessive - Compulsive Disorder, Transcranial Magnetic Stimilation, Intermittent Theta Burst Stimulation, EEG