Characteristics of premenstrual syndrome.

To characterize the symptoms associated with premenstrual syndrome (PMS), the menstrual symptom calendars of 100 women diagnosed with PMS were factor-analyzed. Scores on 18 symptoms were recorded daily for one menstrual cycle prior to the women's first clinic visits. Two factors were found to predominate throughout the cycle: The first included emotional and behavioral symptoms and the second included physical and cognitive symptoms. The two factors were constant throughout all the phases of the menstrual cycle. Emotional symptoms clustered together throughout the menstrual cycle and were the dominant symptoms on factor I. However, they loaded (correlation of the variable with the factor) on factors I and II during the postmenstrual phase. Behavioral symptoms loaded on factor I throughout the menstrual cycle; however, they were prevalent predominantly in the later half of the intermenstrual and the premenstrual phases. Physical symptoms loaded predominantly on factor II and were less prevalent than the emotional symptoms. The cognitive symptoms loaded on factor II during the premenstrual phase. These findings are relevant for defining PMS criteria for women who seek treatment.