LEP and major depressive disorder: One can quickly observe the presence of distinct themes in the hierarchical cloud generated by the query “Lep Bdnf Fto Lepr” (Lep, leptin; Bdnf, brain-derived neurotrophic factor; Fto, fat mass and obesity associated; Lepr, leptin receptor): obesity related words in the upper section, nervous system related words on the lower right, and, in the conjunction, depression related words on the lower left (Figure 3A).