During the menstrual cycle, when progesterone levels are higher, patterns of brain activity emerge that make it more difficult to distinguish between less and more emotionally demanding situations. According to a study led by Professor Macià Buades, from the Faculty of Psychology and the Institute of Neuroscience (UBneuro) of the University of Barcelona, published in the journal Psychological Medicine (Cambridge University Press), these changes are also associated with a lower mood, which affects women's emotional well-being.
The study presents a new and precise perspective on the hormonal modulation of mood in young, healthy women. The findings will enable more personalized approaches to assessing and treating hormone-related mood disorders, such as premenstrual dysphoria (severe mood swings before menstruation).
Unravelling the relationship between hormones and emotional well-being
Some women may be more sensitive to progesterone than others, perhaps because their brains have more progesterone receptors. However, the neural mechanisms linking hormonal load and emotional regulation remain poorly understood.
The study explores how the natural levels of the ovarian hormones estradiol and progesterone influence the parts of the brain involved in emotion regulation, and whether this could help explain differences in mood.
The study involved 116 women with natural menstrual cycles (not using hormonal contraceptives). The team applied neuroimaging techniques (magnetic resonance imaging) to study emotional facial expressions, multivoxel decoding techniques and analyses of hormones present in saliva.
When progesterone levels are higher, brain scans reveal a poorer distinction between less and more emotionally-demanding situations. Specifically, the patterns in brain region known as the lateral frontal pole are more similar to one another, suggesting that the brain is less able to differentiate emotional situations in real life. By contrast, when participants showed a clearer distinction between easy and difficult emotional situations, they tended to report a better mood during the previous week.
