Did you know that 2 to 5% of women of reproductive age are affected by a more severe form of premenstrual syndrome (PMS) known as premenstrual dysphoric disorder (PMDD)? As with PMS, PMDD occurs in the late luteal phase before menstruation; however, along with abdominal pain, headache, and irritability, those affected by PMDD also experience depression and anxiety. Researchers at the National Institutes of Health (NIH) recently discovered that symptoms may be linked to ESC/E(Z) (Extra Sex Combs/Enhancer of Zeste), a gene complex that responds to environmental changes such as sex hormone fluctuations. Implications for future research include investigating abnormal ovarian steroid response in neurons to illuminate the ESC/E(Z) role in brain chemistry.