Fluctuations in progesterone moderate the relationship between daily mood and alcohol use in young adult women

•Progesterone changes interacted with daily mood to predict drinking.•Decreasing progesterone and negative mood predicted drinking days.•Between-person differences in mood further moderated the association.•Increasing progesterone may decrease the likelihood of women drinking to cope. Research has demonstrated associations between hormonal fluctuations during the menstrual cycle and women’s alcohol use. This association has been explained by mood changes that, for some women, accompany decreasing levels of progesterone during the menstrual cycle, particularly during the late luteal/premenstrual phase. The current study examined whether participants’ daily ratings of mood interact with changing levels of progesterone to predict alcohol use. Young adult women attended two sessions scheduled two weeks apart, during which they completed questionnaires and provided salivary samples for the assay of progesterone levels. In the intervening two weeks, participants completed daily logs of their mood, alcohol use, and menses. Ordered Generalized Linear Mixed Models assessed the effects of daily mood (examined as both a within- and between-subject variable) on the likelihood of drinking, as a function of menstrual cycle phase and changes in progesterone across the two weeks. One standard deviation increase in progesterone corresponded to a 1.61 decrease in the odds of drinking. This main effect was moderated by daily mood. Women were more likely to drink during a decrease in progesterone on days they rated their mood as negative, whereas during an increase in progesterone they were more likely to drink on days they reported a positive mood. Between-subject analyses showed that women who reported lower overall mood during the two-week period were more likely to drink with an increase in progesterone and less likely with a decrease. Women’s likelihood to drink increased when they experienced negative mood in the context of decreasing levels of progesterone, whereas the negative-mood/drinking association was mitigated among those with increasing levels of progesterone. However, compared to women who on average had an overall more positive mood, women with an overall lower mood (and corresponding higher levels of depression and anxiety at baseline) did not experience the protective effects of rising progesterone levels on drinking.