Introduction

Alcohol is one of the world's most commonly used drugs, and its misuse, especially among adolescents and young adults, causes serious health, economic and social problems (Goldman et al., 2005). Low to moderate amounts of alcohol are associated with a reduced risk of coronary heart disease, but high alcohol consumption is related to many diseases, such as hypertension and stroke, liver disease and different types of cancer. The estimated economic cost of alcohol abuse in the US, for example, was $184.6 billion in 1998 (National Institute on Alcohol Abuse and Alcoholism (NIAAA), 2000). Furthermore, early alcohol use in adolescents is often associated with other high-risk behaviours, such as antisocial behaviour, use of other drugs, poor school performance and ...