Adolescents make up about one sixth of the world's population, so policy and practice that improves the lives of young people is hugely beneficial now and for the future. In the current economic climate, most countries in Europe are faced with widening socioeconomic inequalities. It is key to our understanding of how these inequalities impact on young people’s health, to be able to track and measure the differences in health outcomes among children of deprived versus affluent families. The Family Affluence Scale (FAS) devised by Professor Candace Currie, of the School of Medicine, has been used to describe and quantify socioeconomic inequalities in health among young people across Europe and North America and these findings have been published by the World Health Organisation in their report ‘Social Determinants of Health and Wellbeing among Young People’. The indicator has been adapted within the context of the Health Behaviour in School-Aged Children (HBSC), a major international study which involves 43 countries across Europe and North America. FAS has been used to demonstrate that material deprivation impacts negatively on wide ranging aspect of adolescent well-being, including mental health, social relations, bullying, physical activity, eating habits and obesity. This evidence has been incorporated into policy events including WHO-HBSC Forums, bringing together policy makers and health programme developers from all over Europe to discuss the relevance of the findings for guiding their work. The Child and Adolescent Health Research Unit (CAHRU), established by Professor Candace Currie in 2000 and at the St Andrews since 2011, has been designated World Health Organisation (WHO) Collaborating Centre for International Child and Adolescent Health Policy.