Treatment refractory PTSD is a chronic and debilitating psychiatric disorder associated with high morbidity. Despite advances in neuroimaging, genetics, pharmacology and psychosocial interventions in the last half century, little progress has been made in altering the natural history of the condition or its outcome. This study would be the first exploration of a surgical therapy for refractory PTSD. The subgenual cingulate plays a role in mechanisms of this disorder and has been successfully targeted with DBS for the treatment of depression The study will proceed in three stages: pre-operative, operative and post-operative. In the pre-operative stage, consent will be obtained and patients will be scheduled for additional investigations, including neuroimaging (MRI), neuropsychological testing, psychophysiological testing, and a pre-operative assessment by the anesthesia service. In the operative stage, patient will have a stereotactic frame attached directly to their skull. The patient will then undergo a computed tomography (CT) scan with the frame in place, followed by transport directly to the operating room. A skin incision will be made and two burr holes drilled through the skull. After target identification DBS electrodes will be inserted and fixed in place. Patients will be then immediately anesthetized (general anesthesia) for the next step of the surgery. This will involve implanting an internal pulse generator (IPG) under the collarbone and connecting it to the DBS electrodes. During the post-operative phase, patients will return to the clinic 2 weeks after surgery.DBS programming visits will happen biweekly for three months, and monthly thereafter.