PROJECT SUMMARY/ABSTRACT A highly effective intervention to prevent perinatal depression, mindfulness-based cognitive therapy for perinatal depression (MBCT), exists; however, critical implementation gaps prevent its wide use. And though universally recommended, not all prenatal care clinics effectively screen for perinatal depression (PD). Overcoming current implementation gaps is imperative to address the public health crisis of high US maternal morbidity and mortality. With prevalence ranges from 11 – 20% of the 3.8 million people who birth every year, PD is one of the most common childbearing morbidities. And deaths of despair (suicide; overdose) is the leading cause of maternal death. Though rates of perinatal depression are higher, mental health care is less available among underserved women [Black and/or Indigenous and/or Medicaid users]. Recent federally funded maternal mortality review results indicate that 100% of perinatal depression related deaths were preventable. Pregnancy is the optimal time to realize prevention: pregnancy timed intervention is both critical (early intervention improves outcomes) and feasible (prenatal care standardly includes 10-12 clinical visits, and pregnant people are highly motivated to receive prenatal care). CenterMom, Inc. is advancing solutions to these problems via the Center M product: an adaptation of MBCT designed to improve intervention delivery in our target population. Center M pilot work indicates the need for smartphone app delivery of PD screening and home practice materials to succeed in this effort. The purpose of the proposed Phase I STTR is to prototype a smartphone app that can effectively deliver appealing PD screening and Center M home practice materials and test the Center M product inclusive of this app. The overarching hypothesis to this line of inquiry is that pregnant people randomized to the app inclusive Center M intervention, vs. treatment as usual (TAU), will receive significantly better PD screening, will have lower rates of PD at 6 weeks postpartum, and will be highly satisfied with their antenatal preventive mental health care. The proposed work is a critical step to achieving MBCT-PD portability within standard prenatal care health systems and acceptability among underserved pregnant people. Our team, including experts in biomedical commercialization, psychology, mindfulness, community-partnerships, Black maternal health, and prenatal care health systems will critically inform two specific aims: Specific Aim 1: Build a Center M app prototype consistent with underserved, pregnant end user needs. We will conduct 4 focus groups consisting of 5 pregnant end users per group (N=20) focusing on identifying user needs. Using this data and preliminary data, we will complete the app prototype. Then we will conduct app prototype usability testing with 20 additional pregnant people (n = 20). Specific Aim 2: Test efficacy and effectiveness of Center M vs. TAU. We will conduct a pilot ran...