Closed-Loop Stimulation in Emotional Circuits for Neuro-Psychiatric Disorders

Psychiatric illnesses are a major public health challenge, with high burdens of disability and few effective treatments. Electrical stimulation of brain areas involved in emotion and cognition may help re-regulate dysfunctional limbic circuits. Despite promising early results, those open-loop therapies have not improved clinical outcomes. Closed-loop approaches may be more effective, as they can respond to fluctuations of brain and emotional state. We discuss the challenges in finding brain signals for closed-loop neurostimulation control and outline two possible routes to a solution. First, we describe how patients with existing deep brain stimulators can help us identify markers for feedback titration, by considering the unique case of a therapy that works for both depression and obsessive-compulsive disorder. Second, we outline a novel approach that adapts brain-computer interface technologies originally developed for paralysis. Both methods may be applicable to multiple diagnoses, and should be feasible with existing clinical hardware.