The primary purpose of this study is to investigate the effect of deep brain stimulation (DBS) implantation in patients with Treatment-resistant Depression (TRD) targeting the ventral capsule/ventral striatum (VC/VS), Brodmann area 25/subcallosal cingulate (SCC), Anterior Limb of Internal Capsule (ALIC), inferior thalamic peduncle (ITP), nucleus accumbens (NAc), lateral habenula (LHb), medial forebrain bundle (MFB), or other unreported nuclei targets.