Alcohol consumption among young people has been linked to a range of negative outcomes, both contemporary (such as lower educational attainment, smoking and criminal behaviour) and later in life (such as increased risk of drug and alcohol dependence and poorer mental and physical health). However, little research has been done looking at how these behaviours and outcomes are related to one another, which are the most important and what the causal links might be. There seems little doubt that excessive drinking among young people is damaging to themselves and potentially to others, but this study is designed to clarify young people's drinking patterns, with particular emphasis on chains of behaviour that may lead to negative outcomes.