More children in the U.S. are being diagnosed with ADHD than even before -- 10.4 million in 2010 -- according to a new study that concluded a staggering rise in diagnoses of 66 percent since the year 2000.

"There is increased concern on behalf of parents and teachers and doctors. There's been a lot more press and advertising and public health announcements around diagnoses and treatment," said Craig Garfield, a researcher at Northwestern University and the lead author of the study. "Therefore, more people are probably asking their doctors about (Attention Deficit Hyperactivity Disorder)."

The study, which will be published in the journal Academic Pediatrics, did not focus exclusively on new diagnoses. Instead, Garfield said researchers analyzed trends using a national sample of visits to more than 4,000 office-based physicians. The 66 percent increase refers to the number of ADHD-related office visits, some new patients and others repeat visits for ongoing treatment, he said.

But the dramatic jump heats up the ongoing debate over whether ADHD is overdiagnosed -- and how many children are over-medicated as a result.

In October, the American Academy of Pediatrics changed its guidelines to suggest that children as young as 4 and as old as 18 could be evaluated and treated for the disorder. Previously, it only targeted those between 6 and 12. A few weeks ago, in a study of 900,000 children in British Columbia, researchers found that younger male students were 30 percent more likely to be diagnosed than their older counterparts, and younger female students were 70 percent more likely, which raised the question of whether immaturity is often mistaken for ADHD.

At first glance, the Northwestern study might add more cause for concern, but Garfield pointed out that even though the diagnoses have increased, treating ADHD with psychostimulants has dropped: In 2000, Ritalin, Concerta, Adderall and other meds were used in 96 percent of treatment visits, compared to 87 percent in 2010.

"One of the real stories here is that there was a decrease in some of those medications prescribed, but there wasn't an increase in other medications that are typically used as substitutes," he said.

Alternate treatments for ADHD have received increased attention recently, with some studies suggesting that a change in diet be considered instead of, or in addition to, medication.

Psychologist L. Alan Sroufe, made waves in February when he published a controversial New York Times op-ed against using Ritalin to treat ADHD at all. His argument: The drug is a poor treatment option because its efficacy goes away with time, long-term effects on children are unknown and parents are in part to blame for their children having the disorder in the first place.

Dr. Harold Koplewicz of the Child Mind Institute promptly wrote a point-by-point rebuttal to the piece, which was published on The Huffington Post's blog.

Still, Garfield said the drops in treatment using stimulants could be related to FDA warnings and increased awareness of side effects, but the study did not offer information on the treatments parents and doctors opted for instead.

Judith Warner, author of "We've Got Issues: Children and Parents in the Age of Medication" told The Huffington Post that the Northwestern results may raise more questions than answers.

"Are the right kids getting diagnosed? Are the kids getting diagnosed getting treated? Are they getting good treatment? Do parents feel like their kids are getting good treatment? All of that is far more complicated," said Warner. "These numbers in and of themselves don't necessarily mean a whole lot. It's always possible that for some reason you're looking at apples and oranges."

A potential positive within the study, Warner pointed to, is that psychiatrists -- as opposed to pediatricians -- are treating 34 percent of ADHD cases, up from 26 percent in 2000. More specialists who are able to spend increased time evaluating children before determining what might be causing their behavior should be a good thing. Of course, Warner added, that trend could have a negative outcome for those in poorer communities where ADHD is often underdiagnosed, and families may not be able to afford access to a specialist.

Garfield agreed that the shift to specialists has its pluses and minuses for that very reason, but overall he considers the fact that more children are being diagnosed a positive.

"ADHD is a diagnosis that has a lot of judgment associated with it from parents and from other people in children's lives, but I have been doing this long enough to see that kids really do respond to the treatment," he said. "So my hope is the trend of increased visits is resulting in better outcomes for kids."