Paula Luper failed her end-of-third-grade test in 1998, leaving 14 questions blank.
"I remember being very embarrassed I couldn't finish," Luper, 18, said. "I didn't tell any of my friends."
A study that was begun that school year in Johnston County, N.C. - one of the largest ever conducted anywhere on attention-deficit hyperactivity disorder - prompted Luper's parents to consult a doctor, who formally diagnosed her with ADHD.
A decade after that original study, researchers are back. They hope to clarify how the disorder evolves as students navigate their teenage years and adulthood.
Luper, who stopped taking ADHD medication last year as a high school junior, had doubts about taking part in the follow-up study. After weeks of consideration, she decided to participate.
Researchers say they need her help. The closest example of a large community-based study of ADHD - outside of the Johnston County one - dates back to the 1960s in California. Researchers at the National Institute of Environmental Health Sciences in Research Triangle Park, University of North Carolina-Chapel Hill and Duke University chose Johnston County because of its diversity and manageable size.
Most of what is known about ADHD stems from smaller clinical studies, predominantly of Caucasian boys with the hyperactive form of the disorder. Much less is known about ADHD in young adults, especially females, African-Americans and children with the inattentive type of ADHD.
"This information is crucial for doctors, therapists, teachers or social workers trying to help youth with ADHD," said Andrew Rowland, now an epidemiology professor at the University of New Mexico.
The original study, involving 6,099 first- through fifth-graders in all Johnston County elementary schools, revealed some alarming initial results. Parent surveys showed that about 10 percent of the elementary school students had been diagnosed with ADHD. The finding challenged previous studies citing estimates that 3 percent to 5 percent of children have ADHD.
The study also indicated that 7 percent of children were taking stimulant medication to help them calm down or concentrate. Many of the children taking stimulants, however, continued to show symptoms of ADHD, suggesting problems with the doses or with how they were taking the medication. ADHD remains hotly debated because some see it as a result of poor parenting, not a disorder, and they worry that the nation is excessively medicating millions of youngsters.
Rowland said hundreds of studies have shown that stimulants, such as Ritalin and Concerta, help children with ADHD concentrate in the short run.
"What is not known," he said, "is how well those medications work over the long term and if they make a difference in important everyday areas like grades, sleep, ability to make friends or get along with family members."
Luper said she began taking Ritalin in the fourth grade. She swallowed a pill with breakfast before school. The drug made her queasy. It made her feel as if she were the only one in a room. Rather than chat with friends as she might normally want to, she would just feel like sitting quietly. But the sacrifice was worth it.
Before that point, anything would distract her - classmates talking, paper being crumpled, a pin dropping.
"I was making better grades than I would without it," she said. "I knew in 10 years it wouldn't matter how I had felt - it would matter what I'd learned."
Denise Luper, a teacher at North Johnston High School, said she didn't see the full effect drugs had on her daughter until she taught her SAT prep in ninth grade. By then, Paula had switched to another medication, Concerta.
"I told my husband I didn't like it," Denise Luper said. "She's just a zombie sometimes. She's there in body, focused, but it's not her. I'm used to this happy-go-lucky person."
Jesse Paul Luper was no fan of the way the drugs seemed to drain his daughter's energy either. He didn't want the medication to slow her down when she competed in volleyball or soccer games.
Gradually, Paula Luper eased off the drugs. Second semester last year, she took a new drug, Strattera, but only in the weeks around major tests or during final exams. This year, she refrained from taking any medication.
"I try to be more alert," she said. "I know if I do bad, I'm going to have to get back on it."
Her teachers say she has compensated well, continuing to earn A's and B's on her report cards.
"She's good about listening and carrying out assignments," said Anne Wyman, her business teacher. "I would not know she had ADHD, if it was not documented."
Still, Luper has continued to make small modifications to cope with ADHD.
In her English class this year, the teacher would assign short stories to read, such as a Sherlock Holmes mystery. But on quizzes afterward, Luper's mind would go blank.
"It was a zoning-out problem," said Curtis Mangum, her English teacher, "not an intelligence problem."
Denise Luper asked the teacher if her daughter could take notes about the stories as she read. Soon, she was acing the quizzes.
Luper's record seems to run counter to one theory researchers think this new study will test - that people with ADHD are more prone to risky behaviors, such as drinking, having unsafe sex or substance abuse.
"There is some evidence that teens with ADHD have more health risk behaviors and more accidents," Rowland said. "We don't know if that is true when you look at a community sample."
But whatever results the new study finds, they could help Paula Luper down the road. After studying at Johnston Community College and East Carolina University, she hopes to become a high school sports coach and a resource teacher.
"Because I'm ADHD," she said. "I want to help kids like me."