Progesterone Levels Linked to Brain Activity and Mood in Women

Study Finds Progesterone Affects Brain Emotion Control

Researchers from the University of Barcelona have found that higher natural progesterone levels in women are linked to less distinct patterns of brain activity in regions involved in emotion control.

The study, published in Psychological Medicine, used MRI scans to observe how ovarian hormones, especially progesterone, influence the brain’s ability to distinguish between different emotional situations.

How the Study Was Conducted

The research involved 116 women who were not using hormonal contraception. Participants completed mood and menstrual cycle questionnaires, provided saliva samples for hormone measurement, and underwent MRI scans.

During the scans, participants performed tasks requiring either a natural or counterintuitive emotional response to happy and angry faces. Machine learning was used to analyze whether the brain could distinguish between 'easy' and 'difficult' emotional tasks.

Key Findings: Progesterone and Mood

When progesterone levels were higher, brain activity in the lateral frontal pole showed less distinction between easy and difficult emotional situations. This suggests the brain may be less able to differentiate emotional demands during high progesterone phases.

Participants with clearer brain distinctions between emotional situations reported better mood in the previous week. This brain mechanism explained about 7% of the variation in mood scores.

Implications for Metabolic and Hormonal Health

Understanding how progesterone affects emotion control in the brain may help explain mood changes that some women experience during their menstrual cycle.

Professor Ulrike Krämer, a neuroendocrinology expert not involved in the study, noted that individual sensitivity to progesterone may vary, possibly due to differences in brain receptor levels. This research could support more personalized approaches to managing hormone-related mood issues, such as premenstrual dysphoria.

Limitations and Next Steps

The study measured hormone levels and brain activity at a single time point, so it cannot establish cause and effect. The findings apply to naturally cycling women and may not generalize to those using hormonal contraception or with different health conditions.

Further research is needed to understand how these brain patterns change over time and whether interventions could help women who are sensitive to hormone-related mood changes.