PROJECT SUMMARY Perinatal mental health conditions are the most common complication of pregnancy and childbirth (1 in 8 women). When left untreated, perinatal depression and anxiety adversely affects the entire family. Significant racial/ethnic, rural/urban, and socioeconomic status disparities exist in the diagnosis and treatment of perinatal depression and anxiety and these inequities are often intersectional. Our previous and extensive work with multilevel stakeholders including well-established community advisory boards, underrepresented and minority birthing people in rural geographies, and state departments of public health demonstrates the importance of social support as a mechanism for reducing disparities in perinatal depression, particularly in rural geographies. Home visiting programs (HVPs) can provide the social support needed to improve mental health outcomes in pregnant and postpartum women. Despite the known benefits of HVPs and the high rates of moderate to severe depressive symptoms among HVP recipients, home visitors report that clients with depression are more difficult to engage; a specific need exists to address perinatal mental health in HVPs. Mothers and Babies, trialed in HVPs by our co-investigator, is an evidence-based cognitive behavioral intervention that has been shown to be effective in reducing depressive symptoms, but barriers remain for maximizing adoption and fidelity within HVPs. Using an evidence-based implementation strategy that tailors implementation delivery to the needs of the specific populations and context may improve fidelity and adoption, particularly in rural states where residents have limited access to care. Our long-term goal is to improve uptake of an evidence-based maternal mental health intervention to reduce disparities in adverse maternal outcomes and improve community health. The objectives of our study are: Aim 1: Adapt implementation facilitation to support uptake of Mothers and Babies using stakeholder input; Aim 2: Analyze the effects of the adapted facilitation on implementation outcomes (i.e., adoption and fidelity) using mixed rapid ethnographic methods; and Aim 3: Determine the effect of adapted facilitation on the clinical outcomes of severity of depressive symptoms and perceived stress. We will conduct a hybrid implementation-effectiveness-context cluster randomized control trial to test the adapted facilitation strategy compared with implementation as usual (i.e., standard education) and will examine the mechanisms of change (i.e., contextual determinants) related to outcomes. The immediate impact of this research will be to show whether adapted facilitation can improve the uptake and fidelity of a maternal mental health intervention like Mothers and Babies across multiple HVP models and thus positively affect depressive symptoms and perceived stress of recipients. Further, our implementation protocol can be used by other states to better integrate other maternal mental health in...