Depression is one of the prevalent mood disorders and it's the second debilitating disorder in the world. Female menstrual cycle is one of natural and psychological stage in fertility period and this cycle has different behavioral symptoms. In this study, changes in depression scores were studied during different phases of menstrual cycle.

During a basic study, 150 fertile women were chosen and were evaluated by Beck and Hamilton Questionnaires during a menstrual cycle. Data were gathered and analyzed by SPSS software.

Thirty four people were removed because of confounding factors. About 53.4% of them were single by the mean age of 22.10 years ( ± 4.67 SD), and 46.6% were married by the mean age of 34.65 years ( ± 7.51 SD). The mean score of Back questionnaire in the first phase was 11.49, in the second phase was 9.65, and in the third phase was 11.87. The score of Hamilton questionnaire in the first phase was 11.03, in the second phase was 9.45, and in third phase was 11.04, which there was significant differences in both of the tests.

Depression scores increase by reduction of hormone levels in days 2–3 and they classified as mild depression on average and during days 11–14. On the other hand, depression scores decreased by increment of hormone levels to maximum during ovulation days, as well as in days 23–26, depression scores increase by reduction of hormone levels and on average they classified as mild depression.