Using daily ratings to confirm premenstrual syndrome/late luteal phase dysphoric disorder. Part II. What makes a "real" difference?

Five degree of change criteria used in previous research to confirm premenstrual syndrome/late luteal phase dysphoric disorder (PMS/LLPDD) based on daily ratings were examined to determine how well each differentiated between women claiming to experience severe symptoms and women with normal menstrual experience. Frequency and nature of stressful events and subjective perceptions of impairment were also examined. Ratings were evaluated in 31 women who met DSM III-R criteria for a provisional diagnosis of LLPDD, and 34 women who reported no premenstrual symptomatology. Ratings for a sample of women taking oral contraceptives and a sample of men were also included for comparison purposes. Results indicated no differences between the groups in the frequency of stressful events. However, the PMS/LLPDD group rated their problems as more disturbing and evidenced a cyclical pattern in the occurrence of negative interpersonal interactions at work that was suggestive of some impaired functioning. None of the five change criteria differentiated the PMS/LLPDD group from the normally cycling No PMS group, and only one differentiated this group from the oral contraceptive No PMS group. This was true whether a liberal or conservative standard of confirmation was applied. The implications of these findings for using daily ratings to confirm PMS/LLPDD are discussed.