Premenstrual symptoms: a reinterpretation.

Conclusions regarding the physiological basis and disruptive effects of premenstrual symptoms may be biased because of the reliance on self-report questionnaires as a source of data. In order to examine this possible bias, women's perceptions of their cycle phase were separated experimentally from actual cycle phase. Women who were led to believe that they were premenstrual reported experiencing a significantly higher degree of several physical symptoms, such as water retention, than did women who were led to believe they were intermenstrual. Thus, because of these psychosocial influences on symptom reports, it seems necessary to reexamine previous conclusions regarding the magnitude of menstrual-related changes as well as their physiolocical basis.