Tracking A Rise In ADHD Diagnosis
IRA FLATOW, HOST:
This is SCIENCE FRIDAY, I'm Ira Flatow. Earlier this week, the New York Times reported new CDC data on diagnosis of attention deficit hyperactivity disorder, ADHD, in kids. And the numbers are startling, with 11 percent of the parents surveyed reporting a diagnosis of ADHD for their school-age kids, higher numbers for some sub-groups of age and gender. That's a big jump. Estimates before that had been that ADHD affected somewhere from three to seven percent of children.
So what's behind the surge in numbers? Is the spike real, or is it just a reporting error? And what does that increase in diagnoses mean? Joining us now to talk about it is William Graf, he's a professor of pediatrics and neurology at Yale School of Medicine in New Haven. Welcome to SCIENCE FRIDAY.
WILLIAM GRAF: Hi Ira, thanks for inviting me.
FLATOW: Were you surprised by these numbers?
GRAF: Yeah, these numbers are pretty high, and it is surprising, and I think that on one hand they're sort of real because we've seen this change over the last two decades as the rates have slowly gone up, and on the other hand they're inflated a little bit, probably because of the way they were obtained.
These are - the CDC did a study, which is like polling data. They - it's called the National Representative randomized Cross-sectional Survey. And it's - this particular trial supposedly was done with land line and cell phone telephone surveys of all households who have children.
There was a similar study just published a couple weeks ago that was on autism, which showed the rate of autism was two percent of the population, which is also very high and was discussed just in the same way. But these are epidemiological survey data, and they're worth something. We have other data to show that the numbers are indeed going up.
FLATOW: Give us an idea again what actually ADHD is, real ADHD.
GRAF: Yeah, I think that's one of the points of the discussion. Probably ADHD is three to seven percent of the population, and we're talking about a rise now, but it has an interesting history. It probably dates back 40 or 50 years. It was called, you know, minimal brain damage a long time ago in the '70s.
The Diagnostic and Statistical Manual III, DSM-III, called it ADD with or without hyperactivity. And then the name sort of changed. DSM-IV called it ADHD. DSM-V will change it slightly differently. You have to remember that ADHD overlaps with other minor neurological - relatively minor. They can cause impairment.
And the three classic symptoms are inattentiveness, impulsiveness, hyperactivity, and we can talk about what that is. And that has to lead to impairment. And there's a couple of reasons why this diagnosis would be controversial, and that is because there's no biological marker for it, because the diagnostic criteria are somewhat subjective and because different people will interpret the impairments and the symptoms differently even in the same child.
FLATOW: Could this not be one of the reasons for over-diagnosis, that these are vague ways of diagnosing some of the symptoms.
GRAF: There's probably a lot of social reasons why and environmental reasons why it could be over-diagnosed. There are also these co-morbidities with ADHD. Probably half of the kids have - who really have ADHD have some form of a learning disability. There are different names that are out there like auditory processing disorder, and the latest is something called executive function disorder. That's the most popular right now.
And I can well see that there'll be a shift in ADHD diagnosis to something else, just like the terms for autism have changed in the last 10 years to spectrum disorders and things like that. So you have changes in the names we give, the labels that we give for these conditions.
FLATOW: Is the diagnoses coming from the parents, the doctors, the teachers? Where are we seeing this increase coming from?
GRAF: So I can list a couple of possible explanations for why the numbers are going up. First of all, it could be that kids are actually changing, and there is actually more ADHD out there. But most people probably don't believe that. Kids are spending more time in front of their computers, and they might be exercising less than in the past. Those are probably true. But whether or not that translates to a diagnosis of ADHD is less clear.
I think some of the reasons, that there's a lot of surveillance for this, so people are looking for it. There's greater awareness and acceptance of the disorder and in part because the pharma industry has direct-to-consumer advertising, and they've succeeded in selling this.
And then adolescents are way up, and that's an interesting sub-group here because the boys in high school, their numbers have jumped, and there's got to be an explanation for why the diagnosis is being made so late. And then lastly we just recently published a position paper through the American Academy of Neurology on pediatric neural enhancement, which is a sub-group that might be taking stimulants and might be coded as ADHD, but actually it's healthy children who are using stimulant medications as study drugs. And that probably explains some of the jump.
FLATOW: You know, there is - if you just think about it, it seems like the jump is occurring at the same time we hear about the epidemic of obesity in children, of type 2 diabetes, of sugar consumption. Have these things been controlled for or thought about as perhaps having some connection?
GRAF: I don't know if the data is so clear on the connection there. But kids are definitely getting heavier. Looking at movement and physical activity and then human activity, the need to move, and this thing called hyperactivity, most studies actually don't show that children with ADHD are moving that much more. They're just fidgeting more. So that's sort of an interesting part of this disorder.
Most kids that I see who have ADHD are actually quite thin. And I don't know if that's a national trend or not.
FLATOW: How about the link to medication? Do we see more kids with the disorder and more medication of those kids?
GRAF: That's where the data comes through beyond the survey science, there are more doctor visits coded for ADHD management. There's more stimulants being prescribed. There's more drug being manufactured, and there's more drug being consumed. And actually last year there was a national shortage of methylphenidate for a while, which means it's actually being consumed.
Another question that comes up periodically is whether people might be motivated to have the ADHD label because of privileges or rights that they might get to take longer for tests. So it would be a diagnostic label which would have some sort of benefit to them, even if they're not taking stimulant medication.
FLATOW: Is there any federal funding for parents or schools or people like that for children who have ADHD? And if so, might that be a motivation?
GRAF: Oh, whether - I think to get Social Security income for a child would depend on the parents' income, and I've heard of that as a possibility, but I don't think it's very common. Certainly the services for children that are publicly funded through public schools are there, the ability to have children be assessed in school.
And that's usually where the assessment takes place. It's not in the doctor's office. It's - these are kids that are not doing well in school, and then the teachers and the school psychologists gather data on that child and bring it back to the physician.
FLATOW: So they're - yeah, are they capable, are they trained enough to be able to actually bring that data to assess, to make the assessment?
GRAF: Again there's - this is a complicated disorder. It's a brain-based disorder when it's real. And then the real question here is, like you say, these numbers are rising, so are these just milder cases. What are the other explanations for that? I think by definition of ADHD, the problem is bad enough that it's causing functional impairment, and that means the child has to be struggling in school. And usually the data is there.
With the milder cases of the kids that are actually normal who are accounting for part of the increase by getting a label of ADHD and then potentially getting stimulants as study drugs, we don't have any data on that because it's not legal, and it's - we believe as the American Academy of Neurology that it's also not ethical to give children medications who are healthy.
FLATOW: So you look at this study, and what's your takeaway message on this?
GRAF: It's sort of the same as the autism that came out a few weeks ago. I don't believe that two percent of children with autism - two percent of children have autism. And I don't think one in five boys in high school has ADHD. But this is a wonderful opportunity to talk about these changes over the course of the last two decades.
This is a national discussion we should be having. Why has this happened, and where are we going with the next two decades? Is this the new normal, that everybody's going to have a label and a medicine in school? This is sort of a sociopolitical discussion that one might have in terms of the competition that kids are forced to have, the school pressures, the No Child Left Behind and the other measures that would put schools under pressure to have better test scores and things like that.
FLATOW: Dr. Graf, thank you for taking time to be with us today. We'll be following this issue with you.
GRAF: Thank you, Ira.
FLATOW: William Graf is a professor of pediatrics and neurology at Yale School of Medicine in New Haven. Transcript provided by NPR, Copyright NPR.