Accelerated rTMS in Hospitalized Patients With OCD: a Feasibility and Mechanistic Study

Intermittent theta burst stimulation (iTBS) targeting the left Dorsolateral Prefrontal Cortex (LDLPFC) will be delivered using a figure-of-eight coil at 50 Hz (3 pulses per burst, 5 Hz burst frequency), with 10 bursts over 2 seconds, followed by an 8-second pause, resulting in a 10-second cycle duration, repeated 60 times for a total of 1800 pulses.

Deep TMS (dTMS) targeting the medial prefrontal cortex (MPFC) will be delivered using an H7 coil at 20 Hz for 2 seconds per cycle, followed by a 20-second pause, resulting in a 22-second cycle duration, repeated 50 times for a total of 2000 pulses.

Patients are admitted to a residential program that includes nonverbal therapies, cognitive behavioural therapy, and from week 3 onward, weekly Exposure Relapse Prevention (ERP) sessions (3 hours/week for 8 weeks; total admission = 10 weeks). ERP includes an inventory of OCD symptoms, psychoeducation on the difference between obsessions and compulsions using an OCD model, and the creation of a stepwise fear hierarchy with exposure and response prevention exercises. Patients practice both during and outside sessions, including at home on weekends. Family involvement is integrated: relatives are invited every three weeks to receive psychoeducation on OCD and ERP, are informed about accommodation behaviors, and may attend a session.