Through the GHS-R1A, the acylated ghrelin modulates systemic metabolism, food intake, and various other peripheral and central physiological functions, such as inflammation, thermogenesis, cardiac output and contractility, the stimulation of gastric motility, prolactin secretion, depression, sleep-wake rhythm, neuroprotection, memory, and reward behavior [38,58,59,60]. The gene discussed is GHRL; the disease is depressive disorder.