In the Porsolt forced swim test, the Zfhx2-deficient mice showed an immobile posture, which is considered as a reflection of a state of behavioral despair and commonly used as an index for evaluating depression-like behavior, for a significantly longer time than the control mice did (day 1, F1,38 = 17.343, p = 0.0002; day 2, F1,38 = 6.739, p = 0.0133, Fig. 4A). This evidence concerns the gene ZFHX2 and major depressive disorder.