1 Introduction Mental health systems are characterised by high fragmentation, lack of coordination, and an insufficient capacity to provide adequate care to those in need, with resulting poor outcomes (Malla et al. 2021; Iyer et al. 2019). Stepped care (SC) is increasingly being adopted around the world as a framework for organising mental health care in diverse contexts, including in schools (Bailey et al. 2022; Gellatly et al. 2024), on digital platforms (Jagayat et al.