Children from homes characterised by poor family functioning are at increased risk of drug initiation and drug use (Hawkins, Catalano & Miller, 1992). Parent-to-child hostility and an absence of warmth are associated with increased cigarette and alcohol use (Brody & Forehand, 1993; Melby et al. 1993; Shelton et al., 2008). Substance use is argued to offer a means of coping with poor family functioning, but may also reflect increased affiliation with peers (who may themselves experiment with and use substances) to gain social support and a sense of belonging (Brody & Forehand, 1993; Melby et al., 1993). Parent-child relationships that are non-supportive or characterised by conflict can also undermine adolescents’ ability to regulate their behaviour in a goal-oriented way, with self-regulation linked in turn to levels of alcohol use (Brody & Ge, 2001).