a, Examples of the clinical responses to ∼90 s of stimulation. Electrodes that demonstrated a positive or negative mood response to stimulation are enlarged for emphasis and shaded with color of respective region. b, Relationship of patient response to literature. c, Covariance matrix of relationship between depression measures (Methods) (left) and heat map of average Likert scores per stimulation condition (right). Somatic symptoms (side effects) of stimulation are also shown. d, Location of stereoelectroencephalography leads in the VC/VS, SGC and OFC with neighboring fiber tracts defined by diffusion tensor imaging. Left, Anterior thalamic radiations and VC–brainstem tracts (inset); middle, forceps minor, stria terminalis/cingulum bundle and uncinate fasciculus; and right, forceps minor and uncinate fasciculus. AMY, amygdala; HAMD, Hamilton Depression Rating Scale; HPC, hippocampus; VAS, Visual Analog Scale.