Sluggish cognitive tempo: the ADHD-like disorder that explains daydreaming?

According to emerging research, many children previously diagnosed with attention deficit hyperactivity disorder could be living with another condition entirely – but not everyone agrees

The tough-minded call it naughtiness. Some parents blame dull teaching. More than a century after it was first described, there are still plenty of people who wonder whether children who can't concentrate at school are really suffering from attention deficit hyperactivity disorder (ADHD). Now a group of researchers think that millions of them are not, but that they are living with something else instead.

Sluggish cognitive tempo (SCT), as the condition has been called, was the big story in the January issue of the Journal of Abnormal Child Psychology. And to some extent it does tidy up a loose end that has been hanging around for decades: many of those diagnosed with ADHD are not hyperactive at all.

Certainly these children struggle to listen to teachers or focus on their schoolwork, and their performance suffers, but they are not racing around the classroom knocking over pencil pots. They are the ones that used to be called daydreamers, and their work doesn't get done just the same.

There is no mention of SCT in the latest Diagnostic and Statistical Manual of Mental Disorders. Instead the book classifies ADHD into three subtypes: one predominantly hyperactive, one predominantly inattentive and one a combination of the two.

According to Dr Russell Barkley, a leading proponent of the SCT theory -- he calls the condition "the second attention disorder" -- between a third and a half of all those diagnosed with the inattentive subtype of ADHD are, in fact, suffering from SCT, and about the same number again remain undiagnosed. In the US, that would add up to around two million children.

"These children are not the ones giving adults much trouble, so they're easy to miss," Dr Keith McBurnett, another contributor to the January special issue, told the New York Times. "Anything we can do to understand what's going on with these kids is a good thing."

Not everyone agrees. Dr Allen Frances at Duke University describes SCT as "a fad in evolution". He is concerned about the possible overdiagnosis of ADHD, now applied to more than six million children in the US, as well as the widespread use of drugs to treat it. Meanwhile in the UK, we are heading in the same direction. Prescriptions for methylphenidate, which is used in the more severe cases of ADHD, rose from 420,000 in 2007 to 657,000 in 2012.

There are also familiar murmurs about "disease-mongering", not to mention the relationship between some of the researchers into SCT and Eli Lilly, a company that is trialling drugs that might treat it. There is even, let's say, a lively debate on Wikipedia about Barkley's role in writing the SCT page. If we want the truth of the matter, as always in science, we will have to wait and see.

© Guardian News and Media 2014

[Image: "Little Girl Reading And Daydreaming In The Living Room," via Shutterstock]