A total of 55 women met full study criteria and started the study. All women were medically and psychiatrically healthy based on a complete physical examination, a structured clinical interview, 12-lead electrocardiogram, clinical blood chemistries, and urinalyses. None of the participants were pregnant based on plasma levels of circulating chorionic gonadotropin hormone (hCG), or nursing, and no one had been pregnant or had an abortion within the previous six months. All women were normally cycling and were not using hormonal contraceptives or any other prescription medications. In addition, no one had any current DSM-IV Axis I psychiatric disorders (American Psychiatric Association, 1994) within the last year, including psychoactive substance abuse or dependence (other than nicotine) based on the Structured Clinical Interview for DSM-IV (SCID I, First et al., 1995), which was conducted by a trained Master's level clinical interviewer. Participants were interviewed on three occasions: first by the investigator during the initial consent meeting, then by the Master’s level clinical interviewer, and finally by the physician during the physical examination. Few women met criteria for any lifetime Axis I disorders;
