(Mayberg et.al. 2005). Regional cerebral blood flow changes (CBF PET) in TRD patients at baseline (row 1) and after 3 months (row 2) and 6 months (row 3) of successful treatment with continuous DBS. Sagittal (left) and coronal (right) views. Baseline CBF abnormalities are seen relative to age- and gender-matched healthy control subjects (NC): increases in subgenual cingulate (Cg25) and decrease in dorsolateral prefrontal (F9), ventrolateral prefrontal (F47) and anterior cingulate (Cg24) cortices (row 1, patients 1–5). Three months of DBS relative to baseline (row 2, patients 1, 3, and 5): decreases in Cg25, hypothalamus (Hth), anterior insula (ins), medial frontal (mF10) and orbital frontal (oF11); increases in prefrontal (F9/46) and dorsal cingulate (cg24). This same pattern is maintained at 6 months, although additional increases are seen in the brainstem (bs) (row 3). Slice location is in millimeters relative to anterior commissure. Numbers are Brodmann designations. L, left. Significant CBF increases in red; decreases in blue (p < 0.001).