Using daily ratings to confirm premenstrual syndrome/late luteal phase dysphoric disorder. Part I. Effects of demand characteristics and expectations

Abstract

Daily symptom ratings were evaluated in 31 women who met DSM III-R criteria for a diagnosis of Late Luteal Phase Dysphoric Disorder (LLPDD), and 34 women who reported no premenstrual symptomatology. Women in both groups were randomly assigned to be aware or unaware of the menstrual cycle focus of the study. Results revealed a consistent pattern of cyclic effects, with higher ratings in the mid-luteal, premenstrual and menstrual phases for many symptoms. Ratings of women reporting severe symptoms were not affected by knowing the purpose of the study and were higher than ratings in the asymptomatic group for many symptoms relevant to the LLPDD diagnosis. Awareness of the study focus did increase cyclicity in the ratings of asymptomatic women aware of the study focus compared with those who were unaware, but these differences were small and most were not significant. The implications of these findings for research and clinical diagnosis of PMS/LLPDD are discussed.