Although multiple treatments for OCD exist, slow symptom decrease, high remission, and significant side effects for some OCD patients limit their efficacy. More research into the precise neural mechanisms and linked cognitive functions in OCD is also necessary. To address both concerns, this study by Dr. Reinhart and his team will test a new, non-invasive, and well-tolerated neuromodulation method for reducing OCD symptoms, based on reward-related high frequency rhythms in the orbitofrontal cortex (OFC; a brain region responsible for reward, decision making and other crucial functions that is affected by OCD). This proposal is based on highly encouraging preliminary data in both sub-syndromal and treatment-resistant populations that shows rapid reductions in OCD behaviors that last at least 1-3 months.

Using high-definition transcranial alternating current stimulation (HD-tACS) guided by EEG brain wave recordings, the study will test whether repetitive and personalized modulation of relevant rhythm activity in the OFC can lead to rapid (within five days) and sustainable (up to three months) OCD symptom reduction. It will also test how much the personalized HD-tACS engages these rhythms, and whether these changes can predict the amount of clinical improvement. This research aims to increase knowledge into OCD neurophysiology and development of effective treatments with minimal side effects.