Healthy lifestyle habits,especially at younger ages,are important both for current health and also for prevention of diseases.Over the past 3 decades,childrens and adolescents lifestyles have changed,with dramatic increases in screen based media use,sedentary behaviorw,which are often acompanied by irregular sleep and eating time,and the associated adverse health outcomes.In the present study,we investigated the effects of environmental stress(ES)on the depression – like behaviors and the plasma concentration of corticosterone(CORT),cholecystokinin(CCK),leptin and neuropeptide Y(NPY)in male and female adolescent rats.We found that ES led to depression – like behaviors in female but not in male adolescent rats.ES induced a significant difference of plasma CORT in female rats(F2,20 = 6.19,p = 0.01)and in male rats(F2,20 = 5.10,p = 0.019).Plasma CORT in both LF and HF group significantly increased in female rats and decreased in male rats compared with CON group(p values < 0.05),respectively.A significant difference in plasma leptin in both gender,respectively,was found(F2,19 = 4.57,p = 0.026 for female rats; F2,20 = 4.85,p = 0.021 for male rats).Plasma leptin in both LF and HF group significantly increased compared with CON group for both genders(p values < 0.05).A significant difference in plasma CCK and NPY in female but not in male rats was found(F2,19 = 5.16,p = 0.018 for CCK,F2,19 = 6.8,p = 0.007 for NPY,in female rats; F2,20 = 0.14,p = 0.89 for CCK,F2,20 = 2.05,p =0.157 for NPY,in male rats).ES induced a significantly increased in plasma CCK and decreased in plasma NPY in both LF and HF group in female rats compared with CON group,respectively(p values < 0.05).Our findings indicated that increased CORT and decreased NPY may be involved in the depression-like behaviors in female rats induced by ES.