Electrophysiological Biomarkers and Treatment Response to Accelerated Transcranial Magnetic Stimulation in Patients With Obsessive-Compulsive Disorder

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

Purpose:

This study aims to evaluate the effectiveness of an accelerated intermittent Theta Burst Stimulation (iTBS) protocol-a non-invasive brain stimulation technique-targeted at the dorsomedial prefrontal cortex (dmPFC) and anterior cingulate cortex (ACC) in patients with treatment-resistant Obsessive-Compulsive Disorder (OCD). Additionally, the study seeks to identify electrophysiological biomarkers (such as EEG microstates and heart rate variability) that may predict which patients are most likely to benefit from the treatment.

Methodology:

The study will include 30 patients aged 18-65 diagnosed with OCD according to DSM-5 criteria who have not responded sufficiently to standard treatments. Participants will undergo an intensive 7-day treatment program consisting of 4 iTBS sessions per day (totaling 28 sessions). Clinical symptoms will be assessed before and after the treatment using standardized scales, including the Yale-Brown Obsessive Compulsive Scale (Y-BOCS), Hamilton Depression Rating Scale (HAM-D), and Hamilton Anxiety Rating Scale (HAM-A). Resting-state EEG measurements and heart rate data will be recorded during and after the sessions to analyze physiological changes.

Goal:

The findings are expected to contribute to the development of personalized neuromodulation protocols and help identify predictors of treatment response for OCD patients.

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.