The #Tamojunto2.0 school prevention program reduced lifetime alcohol use and binge drinking among Brazilian 13-year-olds by increasing negative alcohol beliefs, but had no effect on marijuana, tobacco, or inhalant use.
Read this if you work in substance abuse prevention or education policy.
Alcohol onlySchool prevention program reduced alcohol use through belief change but had zero effect on marijuana
What the researchers found
In a cluster-randomized trial of 5,208 students across 73 public schools, the 12-lesson prevention program indirectly prevented alcohol use and binge drinking by increasing negative and non-positive beliefs about alcohol. Only the direct effect on reducing lifetime alcohol consumption was statistically significant. An unintended indirect increase in binge drinking was observed through increased alcohol knowledge. No effects were found for marijuana, tobacco, or inhalants. Among students who were already users, no effects were found for any substance.
Why it matters
School-based prevention programs have variable effectiveness across substances and cultures. This study shows that changing beliefs can delay alcohol initiation but the same mechanism does not transfer to other substances, suggesting substance-specific prevention strategies may be needed.
The numbers in context
- 5,208 students, 73 schools, 3 Brazilian cities
- 49.4% girls, mean age 13.2 years
- 12 #Tamojunto2.0 lessons delivered by trained teachers
- Effective for alcohol and binge drinking via belief change
- No effect on marijuana, tobacco, or inhalants
- No effect among existing substance users
How the study worked
Cluster-randomized controlled trial. Control group received no intervention. Multiple mediation models with post-estimation adjustment for clustering. Full-information maximum-likelihood for missing data. 9-month follow-up.
Who was studied
5,208 students (mean age 13.2) in 73 public middle schools across three Brazilian cities
What this study cannot tell us
No active control group. 9-month follow-up may be too short for marijuana effects. Brazilian cultural context may not generalize. Implementation fidelity varied across schools.
How to read the evidence
Cluster-randomized controlled trial with mediation analysis. Strong design but limited by short follow-up and no active control.
When this study was published
Published in 2023. Reflects current Brazilian school-based prevention approaches.
The bigger picture
Prevention science shows that what works for one substance may not work for another, and what works in one cultural context may not transfer. This study adds to evidence that substance-specific, culturally-adapted prevention is more likely to succeed than one-size-fits-all approaches.
Questions still open
- Why did the program affect alcohol beliefs but not marijuana beliefs?
- Would a longer follow-up reveal delayed effects on marijuana use?
- Could the program be enhanced with marijuana-specific content?
Read the original research
Changes in alcohol beliefs mediate the effects of a school-based prevention program on alcohol use among Brazilian adolescents.
Addictive behaviors, 137, 107522
Citation
Garcia-Cerde, Rodrigo; Valente, Juliana Y; Sanchez, Zila M. (2023). Changes in alcohol beliefs mediate the effects of a school-based prevention program on alcohol use among Brazilian adolescents.. Addictive behaviors, 137, 107522. https://doi.org/10.1016/j.addbeh.2022.107522