Adaptive (responsive) DBS in psychiatry

Deep-brain stimulation whose parameters change in response to a sensed neural signal — the psychiatric analogue of adaptive DBS in Parkinson's disease, where a subcortical beta rhythm gates stimulation. In psychiatry the sensed biomarker is affective or symptom-state based rather than motor, the relevant dynamics are far slower (mood evolves over hours to days rather than milliseconds), and the control policy may be scheduled (for example circadian), threshold-triggered, or fully closed-loop.

Adaptive motor DBS has reached the clinic in approved devices; adaptive psychiatric DBS remains investigational. The gap is set less by hardware than by two hard problems: finding a reliable, generalizable state biomarker to sense, and designing and validating a slow controller whose infrequent, delayed feedback makes tuning and safety testing much harder than in the fast motor loop.