A Study to Assess the Efficacy, Safety, and Tolerability of Oral NORA520 in Adults With Severe Postpartum Depression

Key Inclusion Criteria: * Are willing and able to provide signed informed consent to participate in the study and to comply with all study procedures and scheduled visits * Are an adult female between 18 and 45 years of age, inclusive; * Have either ceased lactating at Screening, or if still lactating or actively breastfeeding at Screening, agree to temporarily cease giving breastmilk to their infant(s) from just prior to first dose of study drug on Day 1 through Day 14; * Have a negative pregnancy test at Screening and Day 1 (prior to dosing); * Have had a depressive episode that began no earlier than the third trimester and no later than the first 4 weeks following delivery * Are ≤9 months postpartum at Screening. Key Exclusion Criteria: * Have a history or current diagnosis or current treatment of bipolar disorder, schizophrenia, or schizoaffective disorder; * Have had recorded treatment failure of ≥2 different antidepressant classes (e.g., SSRI, SNRI) in the current or previous episode; * Are currently experiencing active psychosis per Investigator assessment, or are taking typical or atypical antipsychotic medication; * Have a history of suicidal behavior within 2 years; * Have a history or current diagnosis of sleep apnea or narcolepsy.