Abstract Dr. Sania proposes to elucidate relationships between maternal depression and child developmental outcomes using prospectively collected data on prenatal and postnatal depression and child development from the PASSECHO study. The parent study is currently collecting prospective data on maternal psychosocial stressors, child development, child nutrition and home environment. Maternal data are collected at 4 time points, once prenatally, and at 1, 4- and 9-years post-pregnancy. Measures of different domains of child development are collected at multiple ages 1 through 11 years. As a part of the re-entry supplement, we propose to pursue the following aims and hypotheses: Aim 1 Depression trajectories: To characterize trajectories of maternal depression based on timing and severity of symptoms prenatally and up to 4-years post-pregnancy. Aim 2 Link to child development: To estimate the effects of maternal depression trajectories on child development at ages between 1 and 4 years. We hypothesize that maternal depression trajectories will be associated with child development scores and that specific patterns of chronicity and severity of symptoms will predict poorer development outcomes better than either pre- or post-pregnancy levels alone. Aim 3 Risk and Resilience: To test the hypothesis that indicators of physical health and early childhood environments moderate the effects of depression on child development.