 Three hundred women with severe premenstrual syndrome will be divided into 3 groups using computer generated random numbers. Group 1 will receiveCombined oral contraceptives COC containing drospirenone drospirenone 3mgEthinylestradiol 0.03mg daily for 21 days starting from the 3rd day of menstruation in addition to oral fluoxetine 20 mg daily. Group 2 will receive fluoxetine 20 mg daily in addition to an oral placebo similar to COC daily for 21 days starting from the 3rd day of menstruation.Group 3 will receive oral placebo similar to COC daily for 21 days starting from the 3rd day of menstruation in addition to a daily oral placebo similar in size, color and structure to fluoxetine. 