Menstrual synchrony by chance when there is menstrual cycle variability. Yang and Schank argued that when there is cycle variability (i.e., either women have irregular cycles, have cycles of different frequencies, or both), most women will have the opportunity to experience synchrony even though it is a result of cycle variability and not a result of a mechanism such as the exchange of pheromones. For example, consider two women A and B. Suppose A has menstrual cycles that are 28 days long and B has cycles that are 30 days long. Suppose further that when A and B become close friends, B
Premenstrual dysphoric disorder ovulation suppression using contraception. Premenstrual dysphoric disorder (PMDD) is a severe form of premenstrual syndrome (PMS). Like PMS, premenstrual dysphoric disorder follows a predictable, cyclic pattern. Symptoms begin in the late luteal phase of the menstrual cycle (after ovulation) and end shortly after menstruation begins. On average, the symptoms last six days but can start up to two weeks before menses. The most intense symptoms occur two days before the start of menstrual blood flow through the first day of menstrual blood flow. The symptoms should cease shortly after the start of the menstrual period. The symptoms in PMDD can