Circuit-based neuromodulation for obsessive-compulsive disorder: a review of prior and emerging methods

Obsessive-compulsive disorder (OCD) is a psychiatric disorder characterized by intrusive and distressing thoughts (obsessions) and repetitive/ritualistic behaviors (compulsions). OCD pathophysiology is thought to arise from dysregulated cortico-striato-thalamo-cortical (CSTC) loops between cognitive and affective circuits. Clinically effective neurosurgical lesions such as cingulotomy and capsulotomy provide insight into mapping distinct symptoms to circuits, and more modern neuromodulation techniques such as transcranial magnetic stimulation (TMS), deep brain stimulation (DBS), and focused ultrasound (FUS) provide the opportunity to develop more precise interventions. We review the literature for neuromodulatory interventions for OCD with a focus on identifying common circuits across modalities. Future directions such as closed-loop DBS and more precisely identifying symptom subtypes are also discussed.