Figure 1. Body weight and depressive-like behavior.

(a) After 4 weeks-long chronic unpredictable mild stress treatment, the stress group mice had significantly lower body weight when compared to the hydrogen-rich water and hydrogen-rich water + stress groups (F_{1, 38} = 15.74, P = 0.0003, post hoc *P < 0.01, n = 11, 11, 10, 10). (b) The stress group mice showed significantly lower sucrose preference percentage in sucrose preference test when compared to the control group (F_{1, 38} = 25.51, P < 0.0001, post hoc ***P < 0.0001, n = 11, 11, 10, 10), and compared to the hydrogen-rich water and hydrogen-rich water + stress groups (F_{1, 38} = 23.29, P < 0.0001, post hoc ***P < 0.0001, **P < 0.001, n = 11, 11, 10, 10). (c) The stress group mice showed significantly longer immobility time in tail suspension test when compared to the control group (F_{1, 33} = 8.784, P = 0.0056, post hoc **P < 0.001, n = 10, 8, 10, 9), and compared to the hydrogen-rich water and hydrogen-rich water + stress groups (F_{1, 33} = 18.64, P = 0.0001, post hoc ***P < 0.0001, n = 10, 8, 10, 9). No significant differences observed among the control, hydrogen-rich water and hydrogen-rich water + stress groups. Data was analyzed using a two-way ANOVA followed by the Bonferroni’s multiple comparisons post hoc test. Error bars represent s.e.m.