EIF4E and major depressive disorder: To rule out developmental/compensatory mechanisms in the depression- and anxiety-like behaviors in Mnk1/2−/− and Eif4e ki/ki mice, we examined whether the depression-like behavior could be induced by pharmacological inhibition of MNK1 and 2 in adult wild-type mice using cercosporamide, an inhibitor of MNK1 and MNK240 (Fig. 4a).