Thesis defense Lindsey Ossewaarde (Donders Series 52)
The mood cycle: hormonal influences on the female brain
On the one hand women feel more irritable, depressive and stressed during the premenstrual phase of the menstrual cycle, when gonadal hormone levels are high but declining. On the other hand, women show more motivated behavior, such as food cravings and increased cleaning behavior, during this phase of the menstrual cycle. In her doctoral thesis, Lindsey Ossewaarde, investigated by using functional magnetic resonance imaging (fMRI) the effects of the menstrual cycle on brain regions known to be involved in emotion regulation and motivation. She showed that healthy young women are more sensitive to stress during the premenstrual phase. Most importantly, this increase in stress-sensitivity was accompanied by changes in brain activity and gray matter volume in regions known to be involved in emotion regulation. In addition, she showed that reward-related brain regions are more active during the premenstrual phase when women are more motivated to clean or eat. Her results can be important for women having premenstrual syndrome (PMS) or premenstrual dysphoric disorder (PMDD).