Premenstrual dysphoric disorder (PMDD) is a more severe form of premenstrual syndrome (PMS), characterized by both psychological and physical symptoms. It generally starts about a week prior to the menstrual period and ceases when the period begins.
It is important for women to be aware of PMDD because its hallmark symptoms -- depression, anxiety, moodiness and irritability -- may be severe enough to interfere with daily life.
Source:
Jacobson, James L. and Alan M. Jacobson. Psychiatric Secrets. 2nd ed. Philadelphia: Hanley & Belfus, 2001.

