New models for menstrual cycle-related mood disorders provide unique opportunities to gain insight into the processing of emotional information and the regulation of mood state by reproductive steroids. This paper reviews the role of reproductive steroids in affect regulation and in premenstrual dysphoric disorder (PMD), parses PMD into component processes that suggest potential mediating neurocircuitry, and highlights the importance of and potential contributors to the differential sensitivity that permits reproductive steroids to destabilize mood in some but not all women.