With more than six million American children having received a diagnosis of attention deficit hyperactivity disorder, concern has been rising that the condition is being significantly misdiagnosed and overtreated with prescription medications.
Yet now some powerful figures in mental health are claiming to have identified a new disorder that could vastly expand the ranks of young people treated for attention problems. Called sluggish cognitive tempo, the condition is said to be characterized by lethargy, daydreaming and slow mental processing. By some researchers’ estimates, it is present in perhaps two million children.
Experts pushing for more research into sluggish cognitive tempo say it is gaining momentum toward recognition as a legitimate disorder — and, as such, a candidate for pharmacological treatment. Some of the condition’s researchers have helped Eli Lilly investigate how its flagship A.D.H.D. drug might treat it.
In an interview, Keith McBurnett, a professor of psychiatry at the University of California, San Francisco, and co-author of several papers on sluggish cognitive tempo, said: “When you start talking about things like daydreaming, mind-wandering, those types of behaviors, someone who has a son or daughter who does this excessively says, ‘I know about this from my own experience.’ They know what you’re talking about.”The Journal of Abnormal Child Psychology devoted 136 pages of its January issue to papers describing the illness, with the lead paper claiming that the question of its existence “seems to be laid to rest as of this issue.” The psychologist Russell Barkley of the Medical University of South Carolina, for 30 years one of A.D.H.D.’s most influential and visible proponents, has claimed in research papers and lectures that sluggish cognitive tempo “has become the new attention disorder.”
Yet some experts, including Dr. McBurnett and some members of the journal’s editorial board, say that there is no consensus on the new disorder’s specific symptoms, let alone scientific validity. They warn that the concept’s promotion without vastly more scientific rigor could expose children to unwarranted diagnoses and prescription medications — problems that A.D.H.D. already faces.
“We’re seeing a fad in evolution: Just as A.D.H.D. has been the diagnosis du jour for 15 years or so, this is the beginning of another,” said Dr. Allen Frances, an emeritus professor of psychiatry at Duke University. “This is a public health experiment on millions of kids.”
Though the concept of sluggish cognitive tempo, or S.C.T., has been researched sporadically since the 1980s, it has never been recognized in the Diagnostic and Statistical Manual of Mental Disorders, which codifies conditions recognized by the American Psychiatric Association. The editor in chief of The Journal of Abnormal Child Psychology, Charlotte Johnston, said in an email that recent renewed interest in the condition is what led the journal to devote most of one issue to “highlight areas in which further study is needed.”
Dr. Barkley declined repeated requests for interviews about his work and statements regarding sluggish cognitive tempo. Several of the field’s other key researchers, Stephen P. Becker of Cincinnati Children’s Hospital Medical Center, Benjamin B. Lahey of the University of Chicago and Stephen A. Marshall of Ohio University, also declined to comment on their work.
Papers have proposed that a recognition of sluggish cognitive tempo could help resolve some longstanding confusion about A.D.H.D., which despite having hyperactivity in its name includes about two million children who are not hyperactive, merely inattentive. Some researchers propose that about half of those children would be better classified as having sluggish cognitive tempo, with perhaps one million additional children, who do not meet A.D.H.D.’s criteria now, having the new disorder, too.
“These children are not the ones giving adults much trouble, so they’re easy to miss,” Dr. McBurnett said. “They’re the daydreamy ones, the ones with work that’s not turned in, leaving names off of papers or skipping questions, things like that, that impinge on grades or performance. So anything we can do to understand what’s going on with these kids is a good thing.”
But Dr. McBurnett added that sluggish cognitive tempo remained many years from any scientific consensus: “We haven’t even agreed on the symptom list — that’s how early on we are in the process.”
Steve S. Lee, an associate professor of psychology at the University of California, Los Angeles, who serves on the editorial board of The Journal of Abnormal Child Psychology, said in an interview that he was conflicted over the journal’s emphasis on sluggish cognitive tempo. He expressed concern that A.D.H.D. had already grown to encompass too many children with common youthful behavior, or whose problems are derived not from a neurological disorder but from inadequate sleep, a different learning disability or other sources.
About two-thirds of children with an A.D.H.D. diagnosis take daily medication such as Adderall or Concerta, which often quells severe impulsiveness and inattention but also carries risks for insomnia, appetite suppression and, among teenagers and adults, abuse or addiction.
“The scientist part of me says we need to pursue knowledge, but we know that people will start saying their kids have it, and doctors will start diagnosing it and prescribing for it long before we know whether it’s real,” Dr. Lee said. “A.D.H.D. has become a public health, societal question, and it’s a fair question to ask of S.C.T. We better pump the brakes more diligently.”
Dr. McBurnett recently conducted a clinical trial funded and overseen by Eli Lilly that investigated whether proposed symptoms of sluggish cognitive tempo could be treated with Strattera, the company’s primary A.D.H.D. drug. (One of Strattera’s selling points is that it is not a stimulant like Adderall and Concerta, medications more susceptible to abuse.) His study, published in The Journal of Child and Adolescent Psychopharmacology, concluded, “This is the first study to report significant effects of any medication on S.C.T.”
An Eli Lilly spokeswoman said in an email, “Sluggish cognitive tempo is one of many conditions that Lilly scientists continue to study to help satisfy unmet medical needs around the world.”
Representatives of the drug companies that make the best-selling medications for A.D.H.D. — Shire (extended-release Adderall and Vyvanse), Novartis (Focalin) and Janssen (Concerta) — said they are not currently conducting research into sluggish cognitive tempo. However, because the new condition shares so many symptoms with A.D.H.D., these products might easily be repositioned to serve the new market.
Dr. Barkley, who has said that “S.C.T. is a newly recognized disorder,” also has financial ties to Eli Lilly; he received $118,000 from 2009 to 2012 for consulting and speaking engagements, according to propublica.org. While detailing sluggish cognitive tempo in The Journal of Psychiatric Practice, Dr. Barkley stated that Strattera’s performance on sluggish cognitive tempo symptoms was “an exciting finding.” Dr. Barkley has also published a symptom checklist for mental health professionals to identify adults with the condition; the forms are available for $131.75 apiece from Guilford Press, which funds some of his research.
Dr. Barkley, who edits sluggish cognitive tempo’s Wikipedia page, declined a request to discuss his financial interests in the condition’s acceptance.
“I have no doubt there are kids who meet the criteria for this thing, but nothing is more irrelevant,” Dr. Frances said. “The enthusiasts here are thinking of missed patients. What about the mislabeled kids who are called patients when there’s nothing wrong with them? They are not considering what is happening in the real world.”
Correction: April 11, 2014
An earlier version of this article misspelled the given name of one of the researchers of sluggish cognitive tempo. He is Stephen P. Becker, not Steven. In addition, the article misstated the institution with which another researcher, Stephen A. Marshall, is affiliated. It is Ohio University, not Miami University in Ohio.