Most minor physical and psychological changes that mark the endocrine cyclicity of women of reproductive age (called premenstrual molimina) are normal phenomena that add to the uniqueness of the female personality. However, for a small percentage of women of reproductive age, cyclic variations in physical and behavioral symptoms may be pronounced.1 The fact that such variations are often difficult to separate from physiologic changes makes an all-or-none accounting impossible; only the recognition of persistent premenstrual difficulties with quantifiable measures of functional or social impairment makes possible the designation of premenstrual syndrome (PMS) (formerly called premenstrual tension). The overlap of PMS symptoms with those of other disorders demands careful attention to the timing and cyclicity of symptoms.