Family-Focused Adolescent &Amp; Lifelong Health Promotion Optimization Trial

The aim of this study is to conduct a multi-country, cluster-randomized factorial trial to optimize the Parenting for Lifelong Health (PLH) for Parents and Teens program in Moldova and North Macedonia. Specifically, this trial will evaluate the effectiveness and cost consequences of three additional intervention components: UNICEF's Helping Adolescents Thrive comics, adolescent peer support based on UNICEF's I Support My Friends intervention, and engagement boosters. ALTERNATIVA will deliver the program in North Macedonia and Health for Youth Association in the Republic of Moldova. This trial is implemented according to the Multiphase Optimization Strategy (MOST). MOST involves three phases. The preparation phase involves adapting and piloting the intervention (Phase 1). The optimization phase involves a factorial trial (Phase 2). Finally, the evaluation phase involves conducting a randomized controlled trial to assess the optimized intervention's effectiveness and cost-effectiveness (Phase 3). A Phase 2 factorial trial is the focus of this registration.

Adolescent mental health is a significant global concern, especially in low- and middle-income countries (LMICs) like North Macedonia and Moldova. Adolescents in LMICs face numerous challenges, including socio-economic stressors, adverse childhood experiences, and limited access to mental health services. Parenting interventions are one approach to reduce risk for poor adolescent mental health outcomes and family maltreatment. Systematic optimization of parenting programs is essential for enhancing scalability and sustainability in low-resource settings. Building on prior research, the "Family-Focused Adolescent \& Lifelong Health Promotion" (FLOURISH) project aims to adapt, optimize, and evaluate a parenting intervention for adolescents aged 10-14 and their caregivers in North Macedonia and Moldova. The project focuses on improving adolescent mental health and well-being in both teens and caregivers, and it is implemented according to the Multiphase Optimization Strategy (MOST) framework. Phase 1 of the project assessed the feasibility of the adapted parenting intervention, which included three components to enhance participation, retention, and effectiveness. The three components were UNICEF's Helping Adolescents Thrive (HAT) comics, peer support, and engagement boosters. This protocol describes the optimization (Phase 2) of the adapted FLOURISH intervention package which will assess the effectiveness and costs of HAT, adolescent peer support, and the engagement boosters, as well as their combinations. The factorial experiment will consist of eight conditions, stratified by country, with each condition reflecting a unique combination of the three components. The results of this study will be used to select the optimized intervention package which will be tested in a randomized trial in the next phase of the FLOURISH project (Phase 3).