Prevalanence and Labels

The Korean study continues to generate discussion. MedPage Today quotes Thomas Insel, MD, director of the National Institute of Mental Health and former director of an NIH-funded Center for Autism Research at Emory University, and John Constantino, MD, a child psychiatrist at Washington University in St. Louis:

Constantino noted that both ends of the spectrum -- not just the milder end -- have begun to incorporate more children than in the past. At the more severe end, some children who would have received a diagnosis of mental retardation are now being included, and at the milder end, some children with behavioral problems and social disability are being included.

"There is a downside to that, that you worry about risks of labeling people who perhaps would be better off without the label," Insel said.

But, he added, "there's also an upside that we should think about, which is the possibility that, for many developmental disorders, sometimes people are on a trajectory that if you can catch them early before they develop the most severe form, you may be able to have a much better outcome."

Constantino agreed, and said that having roughly 2.5% of the population in need of some assistance -- assuming the South Korean figure is correct -- should not be very surprising.

The cutoff for mental retardation encompasses about 2.5% of the population, and there are no quibbles about whether those people need support, he said.

"So why would anybody be either terribly surprised or necessarily even too concerned if now the [autism] instruments are being calibrated in such a way that this is what they're picking up and that this matches reasonable clinical judgement about disability?" Constantino argued.

In his experience, he said, there is not a downside to including children with milder disabilities because they are more responsive to intervention and support.