Alcohol is the drug of choice for many teenagers and their drinking habits arouse considerable concern due to the prevalence of alcohol consumption and the amount drunk. Regular heavy alcohol consumption and binge drinking are associated with physical problems, antisocial behaviour, violence, accidents, suicide, accidental death, injuries and road traffic accidents. Alcohol misuse can also affect school performance and crime. It is associated with a range of mental disorders and can exacerbate existing mental health problems. Adolescents report having more risky sex when they are under the influence of alcohol; they may be less likely to use contraception and more likely to have sex early or have sex they later regret. Early onset of alcohol use has also been found to be associated with an increased likelihood of later alcohol dependence.