Protocol for Repetitive Transcranial Magnetic Stimulation with Symptom Provocation to Treat Obsessive-compulsive Disorder

Obsessive-compulsive disorder (OCD) is a chronic, debilitating neuropsychiatric disorder characterized by the presence of obsessions and/or compulsions that are time-consuming and cause significant functional impairment. Pharmacotherapy and cognitive-behavioral therapy are standard first-line treatments but often fail to provide satisfactory symptom relief, making treatment resistance a significant clinical challenge. Over the last decade, transcranial magnetic stimulation (TMS), a non-invasive brain stimulation technique that allows for focal cortical neuromodulation in humans, has emerged as a promising treatment for OCD. In 2018, the US Food and Drug Administration (FDA) cleared TMS as an adjunctive treatment for adults with OCD, based on procedures to target the anterior cingulate cortex and dorsomedial prefrontal cortex (ACC/dmPFC), while incorporating symptom provocation at the start of each session. Here, a step-by-step TMS protocol for OCD that adheres to the FDA-cleared protocol is detailed, namely an acute cycle of 30 repetitive TMS sessions over 6 weeks with high-frequency stimulation (20 Hz) at 100% of leg motor threshold over the ACC/dmPFC. Treatment consists of 50 trains of 2 s with 20 s of interval between trains, in a total of 2000 pulses per session. Additionally, since each session starts with an individualized symptom provocation task to elicit moderate obsessional distress, a structured description for this procedure is provided, as developed at the Champalimaud Clinical Centre, in Lisbon, Portugal. This article provides guidance on patient preparation, coil targeting, stimulation settings, and symptom provocation, offering a clear framework for clinicians and researchers to implement this neuromodulation approach for OCD.