The Role of GABA and Neurosteroids in Premenstrual Dysphoric Disorder

Inclusion Criteria: * Aged 18 - 45 years old and able to give voluntary written informed consent. * Willing to complete a daily log of mood symptoms for 7 consecutive menstrual cycles: two menstrual cycles during the Screening Phase (Phase 1), one menstrual cycle during the Testing Phase (Phase 2), and four menstrual cycles during the Medication Treatment Phase and Post-Treatment Phase (Phase 3). All subjects who successfully complete Phases 1 and 2, and the Medication Treatment Phase, will be invited to participate in Phase 3 approximately three months later. Phase 3 will involve repeating all procedures conducted in Phase 2, including the daily log of mood symptoms. * Meet DSM-IV criteria for premenstrual dysphoric disorder, confirmed by the Daily Record of Severity of Problems (DRSP; Endicott \& Harrison) for 2 consecutive menstrual cycles (Phase 1). The DRSP is a self-rated symptom checklist, which requires individuals to rate their symptoms of PMDD according to the DSM-IV research criteria scale on a scale from 1 (symptom not present) to 6 (symptom extreme). During the last 7 days of the menstrual cycle compared to days 5-11, patients must have a 30% increase in their average (over 2 menstrual cycles) score for 5 of these 10 symptoms. Symptoms must be "not present" or "minimal" during the postmenstrual week. * Average 19-item Hamilton Depression Rating Scale (HAM-D) scores \< 5 during the follicular phase and \> 16 during the luteal phase. * Have regular menstrual cycle…