It is estimated that 75% women of reproductive age (menarche to perimenopause) experience physical and behavioral symptoms premenstrually and in 40% women symptoms are intense (moderate to severe) and require medical attention. For 3-8 % women premenstrual symptoms are severe enough to interfere with work and interpersonal relationships. Premenstrual Dysphoric Disorder (PMDD) as defined by the Diagnostic and Statistical Manual of Mental Disorders, fourth edition (DSM-IV) research criteria, represents the more severe and disabling end of the premenstrual disorders spectrum. For women with severe premenstrual symptoms or PMDD, these symptoms are bothersome enough to produce an impact on psychological and/or occupational functioning, and professional attention is required.