Besides having a role as a satiety hormone, leptin signaling has been implicated in depression and antidepressant response in humans,29, 30 and neurogenesis in an animal model of stress.27 In particular, Lepr deletion caused depression-like and anxiogenic behaviors and resistance to antidepressant-induced behaviors in animals.28, 31, 64 It remains to be seen to what extent leptin signaling in the brain may have a role in BPD. Here, LEP is linked to major depressive disorder.