Neural Interoceptive Processing is Modulated by Deep Brain Stimulation for Treatment Resistant Depression.

Area of Science:

• Neuroscience
• Psychiatry
• Medical Engineering

Background:

• Depression research is advancing to understand how interoceptive processing influences treatment effectiveness.
• This study investigates if deep brain stimulation (DBS) of the subcallosal cingulate (SCC) impacts cortical interoceptive processing, measured by the heartbeat-evoked potential (HEP), in treatment-resistant depression (TRD).

Approach:

• Eight TRD patients underwent SCC DBS, with electroencephalography (EEG) and symptom severity assessed over six months.
• The primary outcome was the EEG-derived HEP, reflecting cortical processing of heartbeat sensation.
• Cluster-based permutation analyses examined the effects of stimulation and treatment duration on HEP, correlating changes with depression severity (17-item Hamilton Depression Rating Scale).

Key Points:

• After 24 weeks of SCC DBS treatment, HEP amplitude significantly increased (t(7)=-4.40, p=.003), correlating inversely with treatment response latency (rho = -0.75, p=.03).
• An acute effect of DBS also decreased HEP amplitude (t(6) = 6.66, p <.001).
• HEP changes were most prominent over left posterior sensors between 405-425 ms post-stimulus.

Conclusions:

• This study provides brain-based evidence supporting the link between interoception and depression.
• Findings suggest that interoceptive mechanisms contribute to the efficacy of deep brain stimulation for severe depression.