Critical review found little evidence that Project TND prevents drug use | Research

The takeaway

A critical reappraisal of seven evaluations of Project TND, a widely used school drug prevention program, found very few main effects on cigarette, alcohol, and marijuana use.

Read this if you are interested in whether school-based drug prevention programs actually work.

Very few main effects on marijuana, alcohol, or cigarette use across seven evaluations

What the researchers found

This critical review examined all published evaluations of Project Towards No Drug Abuse (Project TND), a school-based prevention program. Across seven evaluation studies, very few main effects were found for cigarette, alcohol, and marijuana use.

While studies reported main effects for "hard drug" use, the reviewer identified numerous threats to validity that may explain these findings, including analytical choices that could inflate results. Similarly, isolated subgroup effects found in early evaluations (such as effects on alcohol use among baseline nonusers) were not replicated in later studies, suggesting they may have resulted from multiple comparisons.

The reviewer concluded there was little evidence to support the assertion that Project TND is an effective drug or violence prevention program.

Why it matters

Project TND was classified as evidence-based by several registries and widely disseminated. This critical review raised important questions about the evidence threshold used to label prevention programs as effective and the consequences of widespread implementation of programs with limited evidence.

The numbers in context

Seven evaluations reviewed. Very few main effects found for cigarettes, alcohol, or marijuana. Reported hard drug effects had "numerous threats to validity." Early subgroup effects were not replicated in later studies.

How the study worked

Critical review of publications from all seven evaluation studies of Project TND, examining main effects on drug use, subgroup analyses, and violence-related outcomes with attention to methodological rigor and replication.

What this study cannot tell us

This is one reviewer's critical assessment and may be subject to its own interpretive biases. Not all researchers may agree with the severity of the methodological concerns raised. The review did not conduct a new analysis of the original data.

How to read the evidence

Critical review of existing evaluations, raising methodological concerns about a program classified as evidence-based.

When this study was published

Published in 2014.

The bigger picture

The broader implication is about how prevention science evaluates its own evidence. When early positive findings are not replicated and may result from analytical choices, the "evidence-based" label can be misleading. The review called for higher standards of evidence before programs are widely disseminated.

Questions still open

Should evidence-based prevention registries revise their criteria? Are other widely disseminated prevention programs similarly lacking in rigorous evidence? What level of evidence should be required before a prevention program is implemented in schools?

Common questions

Does Project TND prevent marijuana use?

This critical review found very few main effects on marijuana use across seven evaluations of the program. Effects reported for "hard drugs" had significant methodological concerns.

Why does this matter?

Project TND was widely disseminated as an "evidence-based" program. If the evidence supporting it is weaker than reported, schools may be investing resources in a program that does not meaningfully prevent substance use.

Read the original research

Is Project Towards No Drug Abuse (Project TND) an evidence-based drug and violence prevention program? A review and reappraisal of the evaluation studies.

The journal of primary prevention, 35(4), 217-32

View on PubMed ↗Publisher’s paper ↗

Citation

Gorman, Dennis M. (2014). Is Project Towards No Drug Abuse (Project TND) an evidence-based drug and violence prevention program? A review and reappraisal of the evaluation studies.. The journal of primary prevention, 35(4), 217-32. https://doi.org/10.1007/s10935-014-0348-1