It is well to be reminded that, FGF2 and FGF9 were found to have the opposite effect through chronic administration of FGFs, that is, FGF2 reduced anxiety- and depression-like behaviors, while FGF9 increased anxiety- and depression-like behaviors (Turner et al., 2008b; Perez et al., 2009). This evidence concerns the gene FGF2 and major depressive disorder.