 - Age 20-45; The selection of the lower limit of this age window is intended to reduce the potential confound that the psychosocial stress of a teenage pregnancy could complicate the relationship between postpartum hormonal events and mood. The upper age limit was selected since pregnancy and childbirth in a woman over this age range could lead to spontaneous menopause and, therefore, our ability to discern the effects of estrogen therapy on mood could be complicated by estrogen s effects on menopausal symptoms. 