RecruitingDevice studySEEG-Guided DBS for OCDThis is a multi-site, double-blinded, randomized, crossover study design for SEEG-guided 4-lead DBS for treatment-refractory OCD, followed by open-label stimulation for an additional 6 months. The study will be conducted in 3 stages: Stage 1 will consist of SEEG brain mapping and optimization of stimulation parameters. Stage 2 will consist of DBS surgery and further optimization of stimulation parameters. Stage 3 will be randomized, crossover treatment, followed by open-label treatment.