Not all young people face equal risks when it comes to problematic substance use. Most risk factors relate to adverse family circumstances, in particular, family socio-economic disadvantage. Children from disadvantaged families face an 80% higher risk of being repeatedly diagnosed with substance use disorders than children from more advantaged families. As well, when children were maltreated, their risk of repeatedly meeting criteria for a substance use disorder was more than 60% higher compared with children who were not maltreated. In addition, when parents had

• symptoms of antisocial personality disorder
• substance use disorders themselves or
• negative relationships with their children

young people were more likely to develop alcohol use disorders. Peers and individual circumstances can also contribute to increased risk. Specifically, having friends with behaviour problems increased young people’s risk for developing an alcohol use disorder. As well, being diagnosed with behaviour disorders, attention-deficit/ hyperactivity disorder or depression increased the risk for developing substance use disorders.