All it took was a map to convince health economists Stephen Hinshaw and Richard Scheffler that it must be some kind of policy issue driving a recent explosion in cases of ADHD.
And a convenient natural experiment — in the form of the federal government’s No Child Left Behind — provided the answer, the two experts argue in a new book. It’s school testing, they say.
“When you look at that, you get the closest thing there is to a smoking gun,” says Richard Scheffler, of the University of California Berkeley who co-authored the book, “The ADHD Explosion”, which was just published this month.
"You get the closest thing there is to a smoking gun."
But it’s not necessarily a bad thing, the authors say, if children are being diagnosed properly, and if they’re getting the right treatments.
There’s no question there’s been a huge increase in the number of kids diagnosed with Attention Deficit/Hyperactivity Disorder, or ADHD. The Centers for Disease Control and Prevention found that about 6.4 million kids aged 4 to 17, or 11 percent of that age group, were diagnosed with ADHD as of 2011.
And CDC documents a steady increase, from 7.8 percent in 2003 to 9.5 percent in 2007 and to 11 percent in 2011— a rate of 5 percent a year.
It looks for all the world like a growing epidemic, says Stephen Hinshaw, a professor of psychology at Berkeley who wrote the book with Hinshaw. But ADHD wasn’t even something people noticed until recently, he says.
“It started about the same time in history that we made kids go to school,” Hinshaw told NBC News in an interview.
Then come the 1990s, and a crisis of falling test scores. “What happened is that a number of states began to pass accountability laws,” Hinshaw said.
In the early 2000s, the CDC began tracking ADHD diagnoses. Hinshaw and Scheffler looked at the maps showing the rates of ADHD, and compared them to a map that showed which states had passed accountability laws.
By the turn of the century, 30 states had passed accountability laws. They tended to be Republican-leaning states in the South, such as North Carolina. In 2007, 15.6 percent of all children in North Carolina had been diagnosed with ADHD at some point, including nearly one in three teenage boys.
This was more than twice the rate in California, with a 6 percent rate.
But this was just a correlation, Hinshaw says. Just because two things happen together in time doesn’t mean one caused the other. They looked at differences in culture, ethnicity, in the number of doctors per capita and at possible other causes. Nothing really explained the different rates of ADHD in different states.
Then No Child Left Behind became federal policy in 2002. One of the first official acts of President George W. Bush after he took office was to ask Congress to write and pass the law.
It called for standardized testing to show if schools were, in fact, educating students. Local state laws often held teachers and principals directly responsible for the results.
“Now what happens is a natural experiment,” says Hinshaw. The other states raced to write accountability laws, requiring schools to show they are actually educating children.
“When you incentivize test scores above all else, there is probably pressure to get kids diagnosed with ADHD."
Hinshaw and Scheffler compared ADHD rates in the 30 states that had been requiring testing with the 20 states that had to play catchup. Rates of ADHD diagnoses soared.
"Children ages 8 to 13, living in low-income homes and in states without previous consequential accountability laws, went from a 10 percent to a 15.3 percent rate of ADHD diagnoses once No Child Left Behind started," they wrote. That's a 53 percent increase over four years.
California’s current rate, post-testing? It’s 7.3 percent. North Carolina’s rate actually fell slightly, to 14.4 percent in 2011.
“When you incentivize test scores above all else, there is probably pressure to get kids diagnosed with ADHD,” Hinshaw said. “We know from our own research that medication not only makes you less fidgety but also can bump up your test scores.”
That would be the benign interpretation, that testing has encouraged parents to get their kids in to see specialists for much-needed medical care. But there’s also a more sinister possibility and one that Hinshaw and Scheffler say is at work in some states.
“If you can identify the children with ADHD, you can take them out of the pool that measures how schools are doing,” says Scheffler. He says some districts — he won’t say where — do seem to have been doing so. State school officials and the federal Department of Education did not respond when contacted by NBC News.
No Child Left Behind ties federal funding to test scores, Scheffler points out.“You can see the incentive for schools to get kids diagnosed with ADHD,” he says.
Either way, Scheffler and Hinshaw say the increase in ADHD cases is real, and it’s not just affecting kids. Recent studies show adult diagnoses are on the rise, too.
“Although often ridiculed, ADHD represents a genuine medical condition that robs people of major life chances,” they write in the book.
"You can see the incentive for schools to get kids diagnosed with ADHD."
Scheffler doesn’t see the increase in adult ADHD diagnoses as surprising. “This has nothing to do with the schools. This has to do with global competition and performance,” he says. People are under pressure to perform better at work.
And news about adult ADHD in turn sends more people to their doctors, and diagnoses spike even more, Hinshaw adds. “Here are we are in 2014 with evidence that medications can benefit. Adult ADHD clinics spring up,” he says.
“That’s not necessarily a bad thing,” says Hinshaw.
What is bad is if ADHD is not being diagnosed with the proper care, Hinshaw says. A 10-minute pediatrician visit is not adequate for an ADHD diagnosis and certainly not as the basis for writing a prescription for a powerful stimulant, such as Ritalin or Adderall, to treat it.
“Many pediatricians are not trained in the emotional disorders of childhood, or not reimbursed for the time it takes,” Hinshaw said. “It is easy to pull out prescription pad at the end of a visit.”
He calls the book a “reality check” and says parents, providers, educators and politicians should take note, and make sure the right kids are being diagnosed, and helped, properly.