NRT-023

The purpose of this research study is to test the study drug, NORA520, as a possible treatment for severe postpartum depression (PPD). The trial aims to determine:
* How well NORA520 is tolerated and what side effects it may cause
* If NORA520 reduces depressive symptoms in subjects with severe PPD
* The amount of NORA520 in the blood at various times after taking the study drug; this provides information that helps determine how often NORA520 should be taken
* In a subset of subjects, the amount of NORA520 in breastmilk at various times after taking it to determine if and how much NORA520 can pass into breastmilk Participate in this study will be randomly assigned to one of 3 different groups. All subjects will take the study drug for 3 days.