There is evidence to suggest that while frequency of alcohol use is associated with a range of negative outcomes, there are distinct risks involved in binge drinking and drunkenness, such as increased aggressive and antisocial behaviour [21,22]. A definition of binge drinking of five or more drinks in a row has been used previously to define problem drinking in epidemiological research and in reports used to inform UK policy decisions [1,2]. The relationship between close friends' alcohol use with adolescent use of alcohol versus problem use may differ and it is potentially informative to explore this.
