Effectiveness of motivational interviewing interventions for adolescent substance use behavior change: a meta-analytic review.
Jensen C.D., Cushing C.C., Aylward B.S. et al. Journal of Consulting and Clinical Psychology: 2011, 79(4), p. 433–440.

Not just for adults, but teenagers and young adults too, with this analysis motivational interviewing seems confirmed as the leading evidence-based approach to reducing possibly or actually risky substance use among non-clinical populations not seeking treatment.

Summary
Evidence for the effectiveness of motivational interviewing to modify health-related behaviour in adults is strong, but evidence in respect of adolescents is just emerging. For the first time, this meta-analysis aimed to summarise information and synthesise data from studies of motivational interviewing interventions intended to promote changes in the substance use of teenagers and young adults.

The analysts searched for peer-reviewed, English language articles from studies which compared post-treatment outcomes from interventions described as motivational interviewing against those from control conditions such as assessment only or an intervention not intended or expected to affect substance use. The people involved had to be (with minor exceptions) aged 21 or less, though their parents might also be involved in the intervention. With relatively few studies, the analytic method did not assume that the impact of these motivational interventions varied only by chance around one 'true' underlying figure, but that differences between the studies might have led to real differences in the impacts of the interventions.

In all 21 studies were discovered. Most documented changes in cannabis and alcohol use, a third smoking, while lesser proportions reported on other drugs. All but four studies recruited samples who were not attending treatment centres but might for example have been identified as substance users in emergency departments or doctors' surgeries, or responded to requests for substance users to join a study. In line with this sampling, 13 of the 21 studies tested brief interventions consisting of just one session of motivational interviewing, and in 17 the motivational intervention was the sole 'treatment'. Additional to or instead of measuring change shortly after the interventions ended, seven studies conducted follow-up assessments over six months later and another four within the next six months.