The order of menstrual cycle phase was counterbalanced between the two groups and across women (i.e., half of the women in each group started testing in the follicular phase). Menstrual cycle phase was estimated based on the modified Daily Ratings Form (see Evans et al., 1998 for details) and ovulation kits, validated using hormone levels. Participants completed the modified Daily Ratings Form each evening throughout the study to track changes in mood symptoms across the menstrual cycle, document the onset and duration of menstruation, and record the number of standard alcoholic beverages consumed each day (one drink = one 12-oz beer, one 5-oz wine, or one shot of liquor). To determine the time of ovulation, participants provided daily urine samples during the midfollicular phase using OvuQuick® (QUIDEL Corp., San Diego, CA; Martini et al., 1994). This test is simple to use and is 96–99% accurate at detecting luteinizing hormone (LH) in urine. Participants were instructed to call the laboratory when they started menstruating or the ovulation kit turned positive. In the event that a woman began menstruating earlier than expected,
