best practice

Home visitation for families composed of low-income unmarried women was found in a narrative review to be mildly effective at 15-year follow-up (Toumbourou et al., 2007, 1 study, N= 743) in reducing for the parent(s):

• number of cigarettes smoked per day (1.50 versus 2.50, p = 0.10);
• number of days having consumed alcohol in the past six months (1.09 versus 2.49, p = 0.03)

Family-based prevention programs (including development of parenting skills, parental support, nurturing behaviours, establishing clear boundaries or rules, parental monitoring, social and peer resistance skills, development of behavioural norms and positive peer affiliations) have shown to be effective in a systematic review (Foxcroft et al., 2011, 12 RCTs) in:

• reducing alcohol misuse in adolescents, with persistence of effects over the medium and longer-term (in 9 of the 12 RCTs analysed)

Comprehensive family-oriented prevention, which includes training for parents, children and whole families, was found to be effective in  one study included in a systematic review (Gates et al., 2006, 9 cluster randomised studies and 8 randomised studies, N = 1230) — although with some disagreement and methodological weaknesses — in:

• reducing lifetime cannabis use and cannabis use in the past year in adolescents (RR =  0.55, 95 % CI 0.32–0.95 and RR = 0.44 95 % CI 0.20–0.96 respectively, at 6 year follow-up) .

Behavioural interventions (face-to-face or group counselling, print materials, interactive computer-based tools designed for patient use, and clinician training and quality improvement programs) implemented in primary care settings and targeting youth not seeking or identified as needing special treatment were found in a systematic review with meta-analysis (O'Connor E. et al., 2020, 29 studies, N=18 353) to have no significant effect in:

• preventing or reducing illicit drug use (SMD= - 0.08, 95% CI = -0.16, p<0.001, 24 studies, N=12 801).

The majority of intervention showed no clear evidence of benefit, and 2 reported increased illicit drug use in youth participating in the interventions for at least 1 drug-related outcome.
However a few showed a benefit for some outcomes in some subgroups, especially  the combination of a clinician interview and an electronic-based intervention  (e.g. computer-based interventions targeting young female adolescents or the computer-based version of the Familias Unidas intervention).

Positive youth development (PYD) interventions i.e. programmes that favour the promotion of positive assets were found in a systematic review with meta-analysis (Melendez-Torres et al., 2016, 10 studies) to have no significant effect in:

• reducing substance use

No pooled analysis could be done on mentoring (understood here to mean a supportive relationship in which one person offers support, guidance and concrete assistance to the partner, based on the sharing of experience and expertise without expectation of personal gain by the mentor — Center for Substance Abuse Prevention 2000) in a systematic review (Thomas et al., 2011) for:

• preventing drug use.

Anti-alcohol/cannabis community interventions were analyzed in a review of reviews (McGrath et al., 2006, 29 reviews) and weak studies due to lack of control groups suggested a reduction in:

• alcohol use;
• cannabis use.

There is evidence from a narrative review including results (Faggiano 2008, 1 RCT, N=271) that such interventions in the short to medium term can be effective at improving young people’s:

• program knowledge (z = 7.03, p < 0.01)
• emotion-focused coping (z = 3.67, p < 0.01)
• social-support coping (z = 2.20; p < 0.05)
• tension-reduction expectancy (z = 2.26; p < 0.05)

Multi-component prevention programs (intervention delivered in more than one setting) have shown in a systematic review (Foxcroft et al., 2011) of 20 RCTs to be effective in:

• reducing alcohol misuse in adolescents (12 of the 20 trials showed some evidence of effectiveness).

Programmes offering strong behavioural life skills development content, emphasised team-building, interpersonal communication methods, and introspective learning approaches focusing on self-reflection were found to be effective in a review of studies (Springer et al., 2004) in:

• reducing 30-day tobacco, alcohol and herbal cannabis (‘marijuana’) use among vulnerable youth.

These programmes were based upon a clearly articulated and coherent programme theory, and provided quality contact with young people