Progesterone blurs emotion-brain signals linked to mood swings

A study of 116 naturally cycling women found higher progesterone levels during the menstrual cycle are associated with less distinct brain activity in emotion-control regions on MRI, making it harder to differentiate between easy and difficult emotional situations and correlating with lower mood (about 7% of mood variation). No similar effect was found for estradiol. The findings could inform personalized approaches to hormone-related mood changes, though causality isn’t established from a single measurement.