rethinkTHC Search
Menu
Study breakdown

Independent evaluations of school drug prevention programs found almost no evidence they work

Systematic ReviewStrong evidence
The takeaway

Of 5,071 publications reviewed, only 6 independent RCTs of 4 school-based drug prevention programs met quality criteria, and only 3 of 42 outcome measures showed significant effects.

Read this if you're involved in choosing drug prevention programs for schools.

3 of 42 outcomes significant across independently evaluated programs

What the researchers found

Researchers conducted a systematic review specifically targeting independently evaluated randomized controlled trials of middle school drug prevention curricula. The distinction of "independent" evaluation was critical because developer-conducted evaluations tend to overestimate effectiveness.

From 5,071 publications, only 13 articles met initial criteria, yielding 6 RCTs of 4 distinct programs. Among these, 42 single-drug outcome measures were reported. Only 3 of the 42 measures showed statistically significant differences between intervention and control groups. One program, Lions-Quest Skills for Adolescence, showed significant positive effects at final follow-up.

The authors concluded there is a striking lack of independent evidence supporting widely used programs, and new approaches to school-based prevention may be necessary.

Why it matters

Schools spend significant resources on drug prevention programs that may not work. When independent evaluators (not the program developers) test these programs, the evidence of effectiveness largely disappears, raising questions about how prevention dollars are spent.

The numbers in context

5,071 publications reviewed. 13 articles met criteria. 6 RCTs of 4 programs identified. 42 single-drug outcome measures. Only 3 showed significant effects. 1 program (Lions-Quest) showed positive final follow-up results.

How the study worked

Systematic review searching PsycInfo, ERIC, Science Citation Index, Social Science Citation Index, CINAHL, MEDLINE, EMBASE, and Cochrane databases from January 1984 to March 2015. Included only independently evaluated RCTs of universal, middle school-based drug prevention curricula available for US dissemination.

What this study cannot tell us

The strict inclusion criteria (independent evaluation, RCT, middle school, US-available) may have excluded effective programs tested in other contexts. Some excluded programs may have positive evidence from non-independent evaluators. The small number of qualifying studies limits conclusions.

How to read the evidence

Systematic review of RCTs with strict independent evaluation criteria. High-quality methodology revealing low evidence base.

When this study was published

Published in 2015. Prevention program evaluation standards may have evolved since.

The bigger picture

The gap between developer-reported and independently-verified effectiveness in school drug prevention mirrors broader concerns about bias in intervention research. This finding should push schools toward programs with independent evidence and away from programs supported only by their own developers.

Questions still open

  • Why do so few programs have independent evaluations? Should schools require independent evidence before adopting prevention curricula? What new approaches to drug prevention might be more effective?

Common questions

Do school drug prevention programs work?
When evaluated by independent researchers rather than program developers, this review found very little evidence of effectiveness. Only 3 of 42 outcome measures showed significant effects across all qualifying studies.
Which school drug prevention programs have the best evidence?
Of the programs meeting this review's strict criteria, only Lions-Quest Skills for Adolescence showed significant positive effects at final follow-up. The authors suggested new prevention approaches may be needed.

Read the original research

Independent Evaluation of Middle School-Based Drug Prevention Curricula: A Systematic Review.

JAMA pediatrics, 169(11), 1046-52

Citation

Flynn, Anna B; Falco, Mathea; Hocini, Sophia. (2015). Independent Evaluation of Middle School-Based Drug Prevention Curricula: A Systematic Review.. JAMA pediatrics, 169(11), 1046-52. https://doi.org/10.1001/jamapediatrics.2015.1736

Explore the wider topic