Brain-Oscillation Synchronized Stimulation of the DMPFC

This trial uses a prospective, randomized, single-blind study design with two treatment arms at the Centre for Addiction and Mental Health (CAMH) in Toronto, ON. The study aims to compare the clinical effects of EEG-triggered, personalized rTMS (i.e., experimental arm) in the treatment of OCD to those of non-EEG triggered, non-personalized rTMS (i.e., active-comparator arm). Additionally, the study aims to compare the modulation of neurophysiological (i.e., EEG) markers of OCD between the two arms. Study treatment will be administered five days per week across a six-week treatment course for a total of 30 sessions. Both rTMS arms will use the same TMS coil, stimulation intensity, number of pulses, and anatomical target (i.e., dorsomedial prefrontal cortex). Clinical outcomes will be measured using the Yale-Brown Obsessive Compulsive Scale (Y-BOCS) with clinical response defined as a ≥30% improvement on the Y-BOCS. The self-reported revised Obsessive Compulsive Inventory (OCI-R) and Clinical Global Impressions - Improvement (CGI-I) scale will also be used. Neurophysiological outcomes will be measured by the change in frontoparietal theta amplitude (i.e., 4-7 Hz) and power of TMS-induced theta oscillations.