280. Enhancement of Neural Interoceptive Processing Observed in Responders to Deep Brain Stimulation for Treatment Resistant Depression

Change in interoceptive processing (i.e., bodily sensation) may be relevant to the mechanisms by which deep brain stimulation (DBS) to the subcallosal cingulate (SCC) affects depression. A measure of interoceptive processing is the heartbeat evoked potential (HEP), which is time-locked to the cardiac cycle. HEP is thought to reflect interoceptive processing of cardiac sensation and is suppressed in depression. Given evidence that SCC DBS impacts autonomic regulation, we predict that reduction of negative mood with DBS relates to change in interoception, indexed by the HEP.