Women’s health experts argue there is an urgent need for carefully designed, gender-specific research to better understand the relationship of female sex hormones to mood states and disorders. Estrogen can be used to treat various mood disturbances in women — such as perimenopausal, postmenopausal and postpartum depression — but the results of these treatments can be difficult to interpret because researchers are only beginning to recognize the complex interactions among estrogens, serotonin and mood.