The epidemiology of premenstrual symptoms in a population-based sample of 2650 urban women: attributable risk and risk factors.

This epidemiologic survey achieved a reliable measure of the prevalence of premenstrual symptoms by avoiding the biases of small or selected samples, anamnestic error, and subjective expectation. From 6232 women (a 78.8% response), aged 20-49 years, identified through a random sample of urban households, the 24-hour prevalence of symptoms was obtained using the Moos' Menstrual Distress Questionnaire, administered without reference to the menstrual cycle. For 71% of the naturally cycling women, current cycle phase was determined by follow-up (n = 2650); but a higher prevalence of severe or moderately severe affective symptoms in the premenstrual compared to the mid-cycle phase was not found. However, observed risk factor interactions led to the conclusion that premenstrual distress is a discrete mood disorder, affecting women aged 25-35 years, with probable ovulatory cycles, and vulnerable to stress; and that the risk of affective symptoms attributable to the premenstrual state was one percent.