This is a single-center 3-stage feasibility study of personalized closed-loop stimulation for treatment resistant Major Depressive Disorder. Depending on participant's results at each stage, he/she might not be eligible to proceed to all 3 stages.
Stage 1 of the study will involve surgically implanting small, thin electrodes in brain regions that regulate depression in order to identify personalized treatment sites. The researchers will test stimulation in the different brain regions and their effect on depression symptoms. The electrodes will be surgically removed at the end of Stage 1.
Stage 2 will involve a second brain surgery to implant the NeuroPace RNS® System. Researchers will use information from Stage 1 to decide where to implant the electrodes of the RNS System. Over the next ~4-12 months, participants will have regular study visits in the clinic where the researchers will determine a personalized brain activity pattern that correlates with depression symptoms and can be paired with stimulation to improve depression symptoms.
Stage 3 will be 12 months long and will involve turning ON and OFF the intervention to test its effectiveness. Over the course of a year, the participant will have two 6-week periods with no stimulation and will receive the intervention for the remainder of the time.
At the end of this stage the participant can choose to continue with long-term follow-up or have the RNS System surgically removed.