LEP and anorexia nervosa: However, some evidence points to leptin as a factor involved in this interaction—the treatment with leptin, an adipocyte-derived hormone3, reduces anxiety in animal models4, as well as hyperactivity and depressive symptoms in anorexia nervosa patients5, and leptin receptor-expressing neurons in the lateral hypothalamus (LH; LepRLH) regulate competing basic needs such as eating, drinking and social exploration6.