Summary: Lisdexamfetamine, a stimulant medication that increases brain activity, was associated with significant reductions in symptoms of sluggish cognitive tempo in adults diagnosed with ADHD.
Source: NYU Langone
Clinical testing of the stimulant lisdexamfetamine has shown promising results in easing symptoms of sluggish cognitive tempo (SCT) in adults living with attention deficit hyperactivity disorder (ADHD).
Sluggish cognitive tempo describes a cluster of symptoms that can include persistent daydreaming, mental fog, low energy, and slow processing speed. For years clinicians and researchers have debated whether SCT is a distinct disorder or a separate symptom profile within ADHD. The new findings add evidence that SCT responds to stimulant treatment in adults with ADHD, while also suggesting that SCT and ADHD may overlap but remain at least partially distinct.
Investigators from NYU Grossman School of Medicine and Icahn School of Medicine at Mount Sinai report that, in a controlled study of 38 adult participants, lisdexamfetamine (marketed as Vyvanse) led to about a 30 percent average reduction in self-reported SCT symptoms. The medication also reduced ADHD symptoms by more than 40 percent and produced measurable improvements in executive function—participants reported fewer episodes of procrastination, better working memory, and improved ability to prioritize tasks.
Published online June 29 in the Journal of Clinical Psychiatry, the study further analyzed the relationship between reductions in ADHD symptoms and improvements in SCT. Researchers estimated that roughly one-quarter of the overall improvement in SCT measures—such as boredom, difficulty staying alert, and confusion—could be attributed to concurrent improvements in ADHD symptoms. This suggests that while some SCT improvements accompany reductions in classic ADHD signs like hyperactivity, impulsivity, and inattention, a substantial portion of SCT improvement appears to arise independently.
“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,” said Lenard Adler, MD, the study’s lead investigator and a psychiatrist who directs the adult ADHD program at NYU Langone Health.
Previous research had demonstrated stimulant benefits for SCT primarily in children with ADHD. Adler and colleagues note that these new adult data are the first to show similar effects in an adult population. They emphasize, however, that it remains unclear whether SCT represents an independent psychiatric disorder and whether stimulant medications would improve SCT symptoms in people who do not meet diagnostic criteria for ADHD.
The clinical trial was funded by Takeda Pharmaceuticals. In the randomized, double-blind portion of the study, several dozen adult volunteers were assigned to receive either daily lisdexamfetamine or a placebo for four weeks. Participants completed weekly standardized assessments that measured SCT symptoms, ADHD symptoms, and multiple aspects of cognitive and executive functioning. After the initial month, participants crossed over: those who had received placebo were switched to lisdexamfetamine and vice versa, allowing researchers to compare symptom changes within individuals.
Adler noted that assessing both SCT and executive function during initial evaluation of adults presenting with attention concerns is important, since treating co-occurring SCT and ADHD may require focused clinical attention. The study’s results support considering stimulant treatment for adults with ADHD who also report prominent SCT symptoms, while acknowledging that more research is needed to define SCT as a separate diagnostic entity and to determine optimal treatment strategies for SCT alone.
The research team included NYU Langone investigators Terry Leon, MS, RN; Taylor Sardoff, BA; and Michael Silverstein, MS. Collaborators were Beth Krone, PhD; Jeffrey Newcorn, MD, from Icahn School of Medicine at Mount Sinai; and Stephen Faraone, PhD, at SUNY Upstate Medical University.
Lenard Adler disclosed receiving grant and research support from several pharmaceutical companies and serving as a paid consultant to multiple organizations; he has also received royalties from NYU for adult ADHD diagnostic and training materials. These relationships are managed under NYU Langone’s conflict-of-interest policies.
About this ADHD research news
Source: NYU Langone
Contact: David March – NYU Langone
Image: The image is in the public domain
Original Research: Findings published in the Journal of Clinical Psychiatry