Systems-Based Neurotechnology for Emerging Therapies (SUBNETS)

The Systems-Based Neurotechnology for Emerging Therapies (SUBNETS) program was created in response to a pressing need. Despite the continued best efforts of the Departments of Defense and Veterans Affairs to protect the health of U.S. servicemembers and veterans, the effects of neuropsychological illness brought on by war, traumatic injuries, and other experiences remain challenging to treat. Current approaches—surgery, medications, and psychotherapy—can often help to alleviate the worst effects of illnesses such as major depression and post-traumatic stress, but they are imprecise and not universally effective. Through SUBNETS, DARPA hopes to generate the knowledge and technology required to deliver relief to patients with otherwise intractable neuropsychological illness.

The SUBNETS vision is distinct from current therapeutic approaches in that it seeks to create an implanted, closed-loop diagnostic and therapeutic system for treating, and possibly even curing, neuropsychological illness. That vision is premised on the understanding that brain function—and dysfunction, in the case of neuropsychological illness—plays out across distributed neural systems, as opposed to being strictly relegated to distinct anatomical regions of the brain. The program also aims to take advantage of neural plasticity, a feature of the brain by which the organ’s anatomy and physiology alter over time to support normal brain function. Because of plasticity, researchers are optimistic that by using SUBNETS-developed technology the brain can be trained or treated to restore normal functionality following injury or the onset of neuropsychological illness.

Through measuring pathways involved in complex systems-based brain disorders including post-traumatic stress, major depression, borderline personality, general anxiety, traumatic brain injury, substance abuse and addiction, and fibromyalgia/chronic pain, SUBNETS will pursue the capability to record and model how these systems function in both normal and abnormal conditions, among volunteers seeking treatment for unrelated neurologic disorders and impaired clinical research participants. SUBNETS will then use these models to determine safe and effective therapeutic stimulation methodologies. These models will be adapted onto next-generation, closed-loop neural stimulators that exceed currently developed capacities for simultaneous stimulation and recording, with the goal of providing investigators and clinicians an unprecedented ability to record, analyze, and stimulate multiple brain regions for therapeutic purposes. The program plan calls for research to be conducted along a schedule of prescribed milestones, culminating in technology demonstrations and submission of devices for approval by the U.S. Food and Drug Administration.

The SUBNETS approach is directed to advance neuropsychiatry beyond the realm of dialogue-driven observations and into the realm of therapy driven by quantifiable characteristics of neural state. In doing so, the program would create one of the most comprehensive datasets of systems-based brain activity ever recorded. If successful, SUBNETS will lead to informed and precise neurotechnological therapy to produce major improvements in quality of life for servicemembers and veterans with neuropsychological illness who have very few options with existing therapies.

SUBNETS and related DARPA neuroscience efforts are informed by members of an independent Ethical, Legal, and Social Implications (ELSI) panel. Communications with ELSI panelists supplement the oversight provided by institutional review boards that govern human clinical studies and animal use.

SUBNETS is part of a broader portfolio of programs within DARPA that support President Obama’s brain initiative.