The rises among children were less steep than among adults, perhaps because prescription rates for children were already much higher. Stan Honda/AFP/Getty Images

A new report shows that prescriptions for attention deficit hyperactivity disorder (ADHD) have skyrocketed in recent years, especially among adults.

The report, by Express Scripts, the nation’s largest prescription drug manager, is likely to widen the debate over whether ADHD is overdiagnosed, and whether medication is prescribed without enough consideration for other forms of treatment.

While some experts say the rise in diagnoses is due to an increasing awareness of the disorder, others believe this study adds to a growing body of evidence suggesting that ADHD prescriptions may be outpacing actual cases of ADHD.

The report was based on the pharmacy records of about 15 million privately insured people in the U.S., including 400,000 who filled at least one prescription for an ADHD medication, the most popular of which are stimulant-based drugs like Adderall and Concerta.

It found that the number of Americans using prescription drugs to treat ADHD rose 36 percent between 2008 and 2012. And the numbers were even larger for some groups. For women between 26 and 34, ADHD-related prescriptions rose 85 percent. Prescriptions for adults in general went up 53 percent, to an estimated 2.6 million Americans.

The rises among children were less steep, but that may be because the rates of prescription were already much higher. In 2012, 5.7 percent of children were prescribed ADHD medication. Some subsets of that group have much higher rates. More than 9 percent of boys aged 12 to 18 were prescribed the drug in 2012, for example.

There are many theories as to why prescriptions are on the rise, but most experts say the numbers show two disparate trends. One is that ADHD is becoming more widely recognized as a legitimate diagnosis, and therefore more people are being diagnosed; the other is that ADHD medication has been overprescribed, used as a solution to other issues such as kids’ behavioral problems in school.

While the study is likely to add to a growing debate about the use of prescription drugs, experts warn that the overmedication question is a complicated one.

“That’s the million-dollar question,” said Paul Morgan, a professor and researcher of diagnosis disparities at Penn State. “You want to be cautious you’re not overdiagnosing, but not so cautious that you aren’t diagnosing people who actually have ADHD.”

The report also found some interesting regional trends. The South had far higher rates of ADHD prescriptions than the rest of the country. South Carolina’s ADHD medication prescription use was found to be 72 percent higher than the national average.

Joseph Austerman, head of the psychiatry and psychology department at the Center for Pediatric Behavioral Health at the Cleveland Clinic, told Express Scripts that the higher numbers in rural states may be due to the lack of access to behavioral health care providers who can properly diagnose the disorder. Low-income children are also more likely to be diagnosed with ADHD, he said.