Infants exposed to impaired parenting as a result of their mothers' major depression and other mental health disorders in the perinatal period are at risk for compromised social interaction and affective and behavioral regulation. Depression is the most frequently reported mental health condition during the perinatal period; about 9% of infants under one year have mothers who experience a major depressive episode. That rate nearly triples to 25% for infants of mothers below 200% of the federal poverty level. In addition to poverty, young maternal age, lack of social support, low education, and adverse childhood experiences are all risk factors for depression, anxiety, and other mental health conditions. Two strands of research point to the need for effective parenting support for mothers following treatment for mental health conditions in pregnancy. First, depressed mothers frequently fail to accurately notice, interpret, or respond sensitively to infant cues. Alarmingly, mothers' impaired parenting of their infants continues even after their depression has been successfully treated. Second, newborns of prenatally depressed women are physiologically dysregulated and hence more challenging to nurture. With the passage of the Affordable Care Act and Maternal, Infant, and Early Childhood Home Visiting, the federal government is supporting states to implement high-quality home visiting programs as part of a comprehensive early childhood system for vulnerable families experiencing the risk factors associated with maternal depression and other mental health symptoms. But two important limitations of home visiting have been identified: child development home visitors are not trained to deal meaningfully with maternal depression and other mental health conditions, and they are often not sufficiently trained to support infant-mother relationships. Our study has the potential to inform intervention programs nationwide by testing the effectiveness of adding a short, attachment-based, home-visiting parenting program to an existing, evidence-based mental health treatment program delivered via community primary care clinics serving pregnant and parenting women from vulnerable populations. The goal of this research is to conduct a randomized controlled trial to evaluate the effectiveness of Promoting First Relationships® for English and Spanish-speaking low-income mothers who were treated for depression or other mental health conditions beginning in pregnancy and as needed in the perinatal year. Treatment will be coordinated through the publicly funded, evidenced-based Mental Health Integration Program for High-Risk Pregnant and Parenting Women (MHIP Moms) in primary care community health centers that target safety-net populations in King County, Washington. Promoting First Relationships® is a research-based, 10-week home visiting program that uses video feedback and strengths-based consultation strategies to increase mothers' parenting competence and confidence. Bilingual community providers will deliver Promoting First Relationships® after a baseline assessment and random assignment at infant age three months. Post tests will occur at infant age six and twelve months. The primary specific aims are to test the effectiveness of PFR to improve parenting quality for low income, English and Spanish speaking mothers who began mental/behavioral health treatment during pregnancy, and to improve social and regulatory outcomes for their infants.