In a transdiagnostic study including patients with anorexia nervosa (AN), hypothalamic amenorrhea, and obesity in addition to HC, clinician-rated depression scores were markedly higher in those persons with the lowest leptin concentrations [22]; to our knowledge, this is the only study to simultaneously include patients with disorders (hypothalamic amenorrhea in addition to AN) entailing low leptin concentrations. This evidence concerns the gene LEP and obesity disorder.