When it comes to children's attention problems, the difference between first and second grade is profound, says a new study from Duke University.

The study, which was recently published online in the Journal of Attention Disorders, says the age at which attention problems emerge makes a critical difference in a child's later academic performance.

When the problems emerged in first grade, children's performance suffered for years afterward. For instance, those children scored lower than their peers on reading achievement scores after fifth grade. The poor performance occurred even if the attention problems were fleeting and improved after first grade.

By contrast, children who developed attention problems starting in second grade performed as well as their peers in later years.

Other studies have noted the link between early attention problems and academic achievement. But the new study is the first to identify the impact of attention problems that emerge in first grade versus those that emerge just a year later.

The research was conducted by Duke psychologists David Rabiner, Madeline Carrig and Kenneth Dodge, the William McDougall Professor of Public Policy and director of Duke's Center for Child and Family Policy. It draws on data from the Fast Track Project, a longitudinal study of the development of conduct problems that has followed 891 individuals in four different locales from kindergarten into adulthood.

The attention study examined academic performance among a subsample of 386 children by looking at grades as well as reading and math scores before and after first grade, and again after fifth grade.

The results may reflect the critical importance of first grade as an academic building block, Rabiner said. Children who suffer from attention problems in first grade fail to acquire key academic skills, and their performance suffers in later years as a result.

Not all first-graders who struggle to focus in school have ADHD, Rabiner added. But whether they have diagnosable ADHD or not, he said it's important to help them at the outset of their academic careers, when they are acquiring essential building block skills.

"Even when these children overcome their attention problems, they continue to struggle in school," Rabiner said. "The earlier we can identify children who are struggling with sustaining attention in the classroom and intervene to help them, the better."

The study emphasized first and second grades, but Rabiner noted that future researchers would do well to look at kindergarten as well. Data for the study was collected beginning in the early 1990s. Since that time, kindergarten has assumed a more important academic role in many schools.