Tests of a drug known to stimulate brain activity have shown early success in reducing symptoms of sluggish cognitive tempo in 38 men and women with attention deficit hyperactivity disorder (ADHD.)A collection of symptoms including persistent dreaminess, fatigue, and slow-working speed, sluggish cognitive tempo has been a subject of debate over whether it is part of, or separate from, ADHD.

Researchers at NYU Grossman School of Medicine and Icahn School of Medicine at Mount Sinai who led the study say the stimulant lisdexamfetamine (sold as Vyvanse) reduced by 30 percent self-reported symptoms of sluggish cognitive tempo. It also lowered by over 40 percent symptoms of ADHD and significantly corrected deficits in executive brain function, with fewer episodes of procrastination, improvements in keeping things in mind, and strengthened prioritization skills.

Publishing in the Journal of Clinical Psychiatry online June 29, the study also showed that one-quarter of the overall improvements in sluggish cognitive tempo, such as feelings of boredom, trouble staying alert, and signs of confusion, were due to improvements in symptoms of ADHD.

The team interpreted that outcome to mean that decreases in ADHD-related incidents of physical restlessness, behaving impulsively, and/or moments of not paying attention were linked to some but not all of the improvements in sluggish cognitive tempo.

"Our study provides further evidence that sluggish cognitive tempo may be distinct from attention deficit hyperactivity disorder and that the stimulant lisdexamfetamine treats both conditions in adults, and when they occur together," says lead study investigator and psychiatrist Lenard Adler, MD.

Adler, who directs the adult ADHD program at NYU Langone Health, says until now stimulants have only been shown to improve sluggish cognitive tempo symptoms in children with ADHD. The NYU Langone-Mount Sinai team's findings, he adds, are the first to show that such treatments also work in adults.

A professor in the Departments of Psychiatry and Child and Adolescent Psychiatry at NYU Langone, Adler says sluggish cognitive tempo is likely a subset of symptoms commonly seen in some patients with ADHD and other psychiatric disorders. However, it remains unclear if sluggish cognitive tempo is a distinct psychiatric condition on its own and if stimulant medications will improve sluggish cognitive tempo in patients without ADHD.

Some specialists have been seeking to qualify sluggish cognitive tempo as distinct, but critics say more research is needed to settle the question.

"These findings highlight the importance of assessing symptoms of sluggish cognitive tempo and executive brain function in patients when they are initially diagnosed with ADHD," says Adler.

For the study, funded by the drug manufacturer, Takeda Pharmaceuticals of Cambridge, Mass., several dozen volunteer participants received daily doses of either lisdexamfetamine or a placebo sugar pill for one month. Researchers then carefully tracked their psychiatric health on a weekly basis through standardized tests for signs and symptoms of sluggish cognitive tempo, ADHD, as well as other measures of brain function. Study participants then switched roles: The one-half who had been taking the placebo started taking daily doses of lisdexamfetamine, while the other half who had been on the drug during the study's first phase started taking the placebo.

Adler has received grant and/or research support from Sunovion Pharmaceuticals, Enymotec, Shire Pharmaceuticals (now part of Takeda), Otsuka, and Lundbeck. He has also served as a paid consultant to these companies, in addition to Bracket, SUNY, the National Football League, and Major League Baseball. He has also received royalty payments since 2004 from NYU for adult ADHD diagnostic and training materials. All of these relationships are being managed in accordance with the policies and procedures of NYU Langone.