Enhanced problem-solving therapy and HIV engagement support to improve perinatal mental health and HIV outcomes in Malawi: A randomized controlled trial - ABSTRACT In sub-Saharan Africa, universal access to antiretroviral therapy (ART) for pregnant and breastfeeding persons, known as Option B+, has rapidly expanded ART access in low and middle-income countries, yielding declines in vertical HIV transmission and improvements in viral suppression. However, disengagement from perinatal HIV care in the perinatal period has emerged as a major challenge to sustaining the success of Option B+. Interventions to support sustained engagement in perinatal HIV care are urgently needed. Perinatal depression (PND) is common among WLHIV and is an important barrier to HIV care engagement. PND is defined as onset of depression in pregnancy and/or within the first 3-6 months postpartum. Among WLHIV in sub-Saharan Africa, 30-40% experience prenatal depression and 20%-30% experience postnatal depression. PND in WLHIV has been linked to increased HIV viral load, postpartum disengagement from HIV care, and reduced infant HIV testing, making PND an important barrier to reaching UNAIDS 2025 goals and ending the HIV epidemic. To address these gaps, NIMH (NOT-MH-21-270) has prioritized testing interventions to address PND among WLHIV in the perinatal period, including their impact on HIV-related outcomes among the mothers and their infants. However, few evidence-based interventions exist that address both perinatal mental health and HIV care outcomes for WLHIV, and even fewer are positioned for rapid translation into practice through incorporation of a rigorous implementation science framework at the effectiveness trial stage. Funded by NIMH (R34MH116806), our team enhanced The Friendship Bench, an evidence-based counseling intervention, to address PND and HIV care engagement for WLHIV. In a pilot individually randomized controlled trial, the Enhanced Friendship Bench demonstrated high levels of acceptability, feasibility, and fidelity to the intervention protocol, as well as preliminary efficacy to improve both PND and engagement in HIV care for WLHIV in Malawi. Building on this work, the objective of this proposal is to evaluate the efficacy of the Enhanced Friendship Bench, compared to usual care, in a fully powered randomized controlled trial to improve PND, HIV care engagement, and secondary infant health outcomes through 12 months postpartum; test hypothesized mediators and moderators that will help elucidate mechanisms of intervention action; and collect key implementation science metrics in a Hybrid Type I design to accelerate translation of findings into practice. Our team is exceptionally well qualified to address these aims given our development and enhancement of the Friendship Bench for perinatal WLHIV; our expertise in HIV, perinatal mental health, and implementation science; and our longstanding research infrastructure in Malawi. Completion of the proposed aims will shift clinical practice by providing a culturally appropriate, scalable counseling intervention that improves PND and engagement in HIV care outcomes for WLHIV that is poised for rapid translation into practice.