Addressing data needs crucial for improving infant, child and youth mental health and substance-related harms in Aotearoa New Zealand: key design and ethical considerations for future research

aim: To evaluate the available data on mental health and substance-related harm among infants, children and young people (ICY) in Aotearoa New Zealand. methods: A scoping review was undertaken to take stock of current data and identify gaps. results: Although there are quality studies, there is a lack of comprehensive, contemporary population-based data to monitor the prevalence and magnitude of mental health conditions and substance use–related harm for children and young people. Existing data are inconsistently measured and are not centrally located or available for all age groups, particularly infants and children. Whānau/ family units are seldom considered or prioritised. conclusions: Aotearoa New Zealand lacks accurate, up-to-date, comprehensive ICY mental health and substance use data to inform investment, service delivery and evidence-based policy. We advocate for enhanced surveillance and monitoring through populationbased mental health and addiction studies with Indigenous and other locally designed measures, and propose key design and ethical considerations for future research. Future research must prioritise Māori and other priority groups, with non-stigmatising, strengthsbased approaches. Addressing these data gaps presents a critical opportunity to improve outcomes for children, young people and their whānau.