In this study, we investigated whether the HPA axis (cortisol), anorexigenic peptides (nesfatin-1), and pro-inflammatory cytokines (C-reactive protein, tumor necrosis factor-α, and interleukin-6, and interleukin-1β) are involved in the mechanism underlying MECT effects in elderly patients with TRD. This evidence concerns the gene NUCB2 and treatment resistant depression.