RecruitingDevice studyDBS for DepressionThe goal of the study is to address the unmet need of TRD patients by identifying brain networks critical for treating depression and to use next generation precision DBS with steering capability to engage these targeted networks. The study's goal will be achieved through 3 specific aims: 1. Demonstrate device capability to selectively and predictably engage distinct brain networks 2. Delineate depression-relevant networks and demonstrate behavioral changes with network-targeted stimulation 3. Demonstrate that chronic DBS using steered, individualized targeting is feasible and safe for reducing depressive symptoms