According to a recent New York Times article, "The Not-So-Hidden Cause Behind the A.D.H.D Epidemic," the sharp increase in the number of diagnoses of Attention Deficit Hyperactivity Disorder over the past few decades--from less than five percent of school-age kids in the 1990s, to 11 percent in 2013--coincides with three important policy changes that incentivized diagnosis.

The first was the writing of A.D.H.D. into the Individuals With Disabilities Education Act of 1991.  This meant that individuals diagnosed with A.D.H.D. could have access to tutors, and could be granted extra time on standardized tests, explains Pacific University sociologist Adam Rafalovich.

A few years later in 1997, changes to the Food and Drug Administration's restrictions made it easier for drug companies to market directly to the public.  Teachers and parents became aware that A.D.H.D. medications existed.  "The diagnosis became increasingly normalized, until it was viewed by many as just another part of the experience of childhood."

The third policy change associated with increases in A.D.H.D. diagnoses was discovered by Stephen Hinshaw (professor of psychology at University of California, Berkeley) and his team, who were puzzled by state variation in rates of A.D.H.D. (the rate is twice as high in North Carolina than in California, for instance).  They looked at a number of possible sociological factors (such as race, income, differences in diagnostic tools, types of health insurance, cultural values, and public perceptions of mental illness)--none of which were found to have a significant effect on diagnoses.  However they did find that "when a state passed laws punishing or rewarding schools for their standardized-test scores, A.D.H.D. diagnoses in that state would increase not long afterward. Nationwide, the rates of A.D.H.D. diagnosis increased by 22 percent in the first four years after No Child Left Behind was implemented."

The correlation may be explained by the fact that A.D.H.D. medication boosts test performance by allowing children to focus better and not be a distraction to others.  In addition, some school districts remove the test scores of children diagnosed with A.D.H.D. from the school's official average.  Together, says Hinshaw, these provide "incentives to boost the diagnosis of the disorder, regardless of its biological prevalence."

Read more:
http://www.nytimes.com/2013/10/20/magazine/the-not-so-hidden-cause-behind-the-adhd-epidemic.html?pagewanted=1&_r=3&ref=todayspaper

TeachingwithData.org resources:
Data Resource Center for Child & Adolescent Health (http://www.childhealthdata.org/browse/rankings)