Mental health disorders such as depression and anxiety affect millions of people worldwide and are associated with increased morbidity and healthcare costs .Although, several therapeutic modalities such as pharmacotherapy and psychotherapy appear effective in treating these disorders, evidence suggests that these treatments are underused. Physical activity (PA) has positive impacts on mental health and psychological wellbeing. Some researchers believe that PA is a useful tool for preventing and easing depression symptoms. Due to the fact that depression symptoms among Iranian, especially young women, are increasing and antidepressant medication is strongly used to ease this disorder, the purpose of this study was to investigate the effects of 6 weeks physical activities on the level of depression in University female students. In this study 792 subjects aged 18-20 years; mean 18.8±0.7 years enrolling in P.E courses were asked to complete the Beck Depression Inventory (BDI), 75 of subjects showing mild-to-moderate depressive symptoms, as measured by BDI scale, were randomly divided into aerobic, swimming and control groups. Aerobic and swimming groups took part in a training protocol consisting of 6 weeks, 3 days a week, 60 minutes a day. t.test, one-way ANOVA and Duncon follow up test at α= 0.05 level were used to analyze the data. The results of ANOVA showed that there is a significant difference in depression level among three groups in post test (α = 0.02). The results of Duncon follow up test showed that there is only a significant difference between aerobic and control group (α = 0.05).When the effect of PA on the level of depression was concerned, the results of T-paired test showed that there is a significant differences between pre-test and post-test of all subjects who took part in 6 weeks PA (α=0.001). The results of the present study indicate that different kind of physical activities have a positive effect on depression symptoms. This tool as well as medication and psychotherapy can be used to reduce the level of depression. So, it can be concluded that PA may play an important role to ease and reduce the depression symptoms of Iranian young female students.
