PROJECT SUMMARY This K99 application aims to determine pathways by which gestational diabetes mellitus (GDM) and prenatal depression affect postpartum maternal mental health, neonatal brain function, and toddler brain-behavioral development. There is a bidirectional association between GDM and depression which affect approximately 10% and 13% of women in the United States respectively and disproportionately affect women from ethnic and racial minority groups. Both conditions are independently associated with adverse neurodevelopmental outcomes in offspring including increased risk for social-emotional and attentional deficits. Despite the