Menstrual Cycle Modulation of Neural Reward Responsiveness and its Associations with Anhedonia

During their childbearing years, women are nearly twice as likely as men to be diagnosed with depression. Despite this stark sex difference, there is a dearth of research examining the effects of the menstrual cycle and ovarian hormones on neural mechanisms underlying depression. Reduced neural reward responsiveness is linked to depression and anhedonia, and prior studies suggest that reward responsiveness may be modulated by ovarian hormones. In a sample of 74 naturally-cycling undergraduate women, the present study employed a within-subject design and multilevel modeling to examine effects of menstrual cycle phases (i.e., early follicular, periovulatory, and mid-luteal phases) and ovarian hormones (i.e., estradiol and progesterone) on an EEG measure of neural reward sensitivity—the Reward Positivity (RewP)—and associations between the RewP and anhedonia. Anhedonia scores were collected at a baseline session and the RewP and salivary hormone concentrations were collected once in each cycle phase. While the RewP did not vary by cycle phase, the RewP was most enhanced when both estradiol and progesterone were above the intra-individual average. Additionally, women with elevated anhedonia were characterized by a reduced RewP in the periovulatory phase as compared to the mid-luteal phase. Finally, the negative association between the RewP and anhedonia was strongest in the periovulatory phase. The present findings suggest that distinct patterns of variability in the RewP across the menstrual cycle may be associated with anhedonia. Future work should further examine these possibilities via longitudinal designs and hormone administration studies.