Evidence supporting such an involvement was observed in two ways: (i) longitudinal Hb volume change following DBS treatment differed in SCC-DBS responders compared to non-responders; (ii) active SCC-DBS stimulation acutely modulated Hb's functional connectivity to a number of regions that are implicated in brain-wide depression networks (54–57). This evidence concerns the gene GSTM1 and depressive symptom measurement.