Robyn Stein De Luca: The good news about PMS

Everybody knows that most women go a little crazy right before they get their period, that their reproductive hormones cause their emotions to fluctuate wildly. Except: There s very little scientific consensus about premenstrual syndrome. Says psychologist Robyn Stein DeLuca, science doesn t agree on the definition, cause, treatment or even existence of PMS. She explores what we know and don t know about it and why the popular myth has persisted.