Alcohol and drug use are highly prevalent and problematic among young people, and the link between childhood behaviour problems and adolescent substance misuse is well-recognised. In this study, Canadian researchers set out to examine whether a two-year prevention programme in childhood could stop substance misuse problems in later life.
172 boys with disruptive behaviour participated in the study. They all came from low socio-economic backgrounds, and were a subsample from the Montreal Longitudinal and Experimental Study of Low SES boys, a kindergarten cohort which was initiated in 1984.
46 boys and their parents took part in the two-year intervention programme, when they were aged between 7 and 9 years old. The programme included social skills training for the boys at school, to help promote self-control and reduce their impulsivity and antisocial behaviour, as well as parent training to help parents recognise problematic behaviours in their boys, set clear objectives and reinforce appropriate behaviours. A further 42 boys received no intervention and acted as the control group.
The remaining 84 boys were assigned to an intensive observation group, which differed from the controls in that their families were visited in their homes by researchers, attended a half-day laboratory testing session, and were observed at school. All the boys were followed up until the age of 17, to assess their use of drugs and alcohol.
The researchers found that levels of drug and alcohol use across adolescence were lower in those boys who received the intervention. The reduction in substance use continued through the boys' early adolescence right up to the end of their time at high school.
Researcher Natalie Castellanos-Ryan, of the Department of Psychiatry at Université de Montréal and Centre Hospitalier Universitaire Sainte Justine, Canada, said: "Our study shows that an two-year intervention aimed at key risk factors in disruptive kindergarten boys from low socioeconomic environments can effectively reduce substance use behaviours in adolescence -- not only in early adolescence but up to the end of high school, eight years post-intervention. This finding is noteworthy because the effects are stronger and longer-lasting than for most substance use interventions that have been studied before."
Dr Castellanos-Ryan added: "The intervention appeared to work because it reduced the boys' impulsivity and antisocial behaviour during pre-adolescence - between the ages of 11 and 13. Our study suggests that by selectively targeting disruptive behaviours in early childhood, and without addressing substance use directly, we could have long-term effects on substance use behaviours in later life. More research is now needed to examine how these effects can generalize to girls and other populations, and to explore aspects related to the cost/benefit of this type of intervention."