Fifth-grade students who took part in comprehensive, interactive school-based prevention programs starting as early as first grade were half as likely as their peers to use alcohol or other drugs, act out violently, or engage in sexual activity, according to a new study from the National Institute on Drug Abuse (NIDA).

"This study provides compelling evidence that intervening with young children is a promising approach to preventing drug use and other problem behaviors," said NIDA Director Nora Volkow. "The fact that an intervention beginning in the first grade produced a significant effect on children's behavior in the fifth grade strengthens the case for initiating prevention programs in elementary school, before most children have begun to engage in problem behaviors."

Researchers led by Brian Flay of Oregon State University studied students at 20 public elementary schools in Hawaii who had participated daily in Positive Action (PA), a comprehensive K-12 program focusing on social and emotional development. Students who had received the PA lessons the longest had the least amount of problem behaviors, the study found.

The authors will next look at whether the PA program had lasting effects on older students.

The study was published online ahead of print June 18, 2009 in the American Journal of Public Health.