Bipolar II Disorder, Most Recent Episode Major Depressive

Neurons are specialized types of cells that are responsible for carrying out the functions of the brain. Neurons communicate with electrical signals. In diseases such as major depression this electrical communication can go awry. One way to change brain function is using electrical stimulation to help alter the communication between groups of neurons in the brain. The purpose of this study is to test a personalized approach to brain stimulation as an intervention for bipolar depression The study researchers will use a surgically implanted device to measure each individual's brain activity related to his/her depression. The researchers will then use small electrical impulses to alter that brain activity and measure whether these changes help reduce depression symptoms. This study is intended for patients with major depression whose symptoms have not been adequately treated with currently available therapies. The device used in this study is called the NeuroPace Responsive Neurostimulation (RNS) System. It is currently FDA approved to treat patients with epilepsy. The study will test whether personalized responsive neurostimulation can safely and effectively treat bipolar depression.