The Effectiveness of Family Interventions in Preventing Adolescent Illicit Drug Use: A Systematic Review and Meta-analysis of Randomized Controlled Trials

In order to quantify the effectiveness of family interventions in preventing and reducing adolescent illicit drug use, we conducted a systematic review and meta-analysis of randomized controlled trials. We searched the Cochrane Database of Systematic Reviews, Educational Research Information Centre (ERIC), MEDLINE, Embase, and PsycINFO for studies published between 1995 and 2013. Results were described separately for different outcomes (marijuana vs. other illicit drugs) and intervention types (universal, selective, and indicated prevention). Meta-analyses were performed when data were sufficient (e.g., marijuana and other illicit drug initiation in universal samples), using random effect models. Otherwise, we provided narrative reviews (e.g., regarding selective and indicated prevention). Thirty-nine papers describing 22 RCTs were eligible for inclusion. Universal family interventions targeting parent–child dyads are likely to be effective in preventing (OR 0.72; 95 % CI 0.56, 0.94) and reducing adolescent marijuana use, but not in preventing other illicit drugs (OR 0.90; 95 % CI 0.60, 1.34). Among high-risk groups, there is no clear evidence for the effectiveness of family interventions in preventing and reducing illicit drug use and drug disorders. The three small RCTs among substance-(ab)using adolescents gave some indication that programs might reduce the frequency of illicit drug use. Family interventions targeting parent–child dyads are likely to be effective in preventing and reducing adolescent marijuana use in general populations, but no evidence for other illicit drug use was found. We underline the need to strengthen the evidence base with more trials, especially among at-risk populations.