To the Editor: In the April 2011 issue of the Journal, Dias et al. (1) classify bipolar women as having premenstrual exacerbation of symptoms based on retrospective questioning. The poor reliability of self-reported premenstrual mood change has been known for decades (2), and prospective measurement has become the standard (3).

Two unpublished analyses cast doubt on the validity of retrospective reports of premenstrual exacerbation in women with major depressive disorder. Kornstein et al. (4) analyzed data from a large multicenter treatment study of chronic depression in which women were asked, "Are you aware of regularly occurring worsening of your mood related to your menstrual cycle?" A subset of 97 women maintained a daily log of mood symptoms over one menstrual cycle prior to treatment. There was no association between the two types of reports: 27% of women with and 26% of women with no self-reported premenstrual exacerbation had prospectively confirmed premenstrual exacerbation on daily ratings. Harvey et al. (5) examined women in clinical trials of antidepressant efficacy. Premenstrual syndrome was reported by 18 of 27 women. When visit-to-visit changes in HAM-D scores were examined as a function of phase of the menstrual cycle at the time of rating, premenstrual exacerbation was apparent in 26% of the women. There was no association (r²=–0.002) between self-reported premenstrual syndrome and premenstrual exacerbation score.

It is challenging to collect the daily mood data that are considered the gold standard in studies of premenstrual mood change, leaving self-report as the measure clinicians have tended to use (4). Although retrospectively reported premenstrual exacerbation has been associated with a more symptomatic and relapse-prone phenotype in bipolar women (1) and longer duration of depressive episodes in women with major depression (4), it is not a valid measure of symptom worsening near the onset of menses.

Dias et al. (1) may be able to make an important contribution to the literature if the Systematic Treatment Enhancement Program for Bipolar Disorder (STEP-BD) study called for the recording of dates of menses throughout the study, as was done in the Sequenced Treatment Alternatives to Relieve Depression study (STAR*D). Only access to dates of menses will permit the placement of observed acute exacerbation of symptoms during the treatment of women with antidepressants (5) into the context of the menstrual cycle.