SCT alone was not studied
The trial had some limitations, mainly that it was an initial study with a modest sample size, Dr. Adler said. It also did not examine SCT alone, “so we can’t really say whether the stimulant medicine would improve SCT in patients who don’t have ADHD. What’s notable is when you look at how much of the improvement in SCT was due to improvement in ADHD, it was just 25%.” This means the effects occurring on SCT symptoms were not solely caused by effects on ADHD.
he said.
Dr. Adler would like to see treatment studies of adults with ADHD and SCT in a larger sample, potentially with other stimulants. In addition, future trials could examine the effects of stimulants on adults with SCT that do not have ADHD.
The results of this trial underscore the importance of evaluating adults with ADHD for comorbid symptoms, such as executive function and emotional control, he continued. “Impairing SCT symptoms may very well fall under that umbrella,” Dr. Adler said. “If you don’t identify them, you can’t track them in terms of treatment.”
SCT as a ‘flavor’ of ADHD
The outcome of this study demonstrates that lisdexamfetamine significantly improves both ADHD symptoms and SCT symptoms, said David W. Goodman MD, LFAPA, an assistant professor in the department of psychiatry and behavioral sciences at Johns Hopkins University, Baltimore.
Dr. Goodman, who was not involved in the study, agreed that clinicians should be aware of SCT when assessing adults with ADHD and conceptualize SCT as a “flavor” of ADHD. “SCT is not widely recognized by clinicians outside of the research arena but will likely become an important characteristic of ADHD presentation,” he said in an interview.
“Future studies in adult ADHD should further clarify the prevalence of SCT in the ADHD population and address more specific effective treatment options,” he said.
James M. Swanson, PhD, who also was not involved with the study, agreed in an interview that it documents the clear short-term benefit of stimulants on symptoms of SCT. The study “may be very timely, since adults who were affected by COVID-19 often have residual sequelae manifested as ‘brain fog,’ which resemble SCT,” said Dr. Swanson, professor of pediatrics at the University of California, Irvine.
The study was funded by Takeda Pharmaceutical, manufacturer of lisdexamfetamine. Dr. Adler has received grant/research support and has served as a consultant from Shire/Takeda and other companies. Dr. Goodman is a scientific consultant to Takeda and other pharmaceutical companies in the ADHD arena. Dr. Swanson had no disclosures.