Center for ADHD
Center for ADHD

Evaluating Assessment and Medication Treatment of ADHD in Children with Down Syndrome

Grant #: R61HD100934
PI: Anna Esbensen, PhD & Tanya Froehlich, MD
Collaborators: Jeff Epstein, PhD; Julia Anixt, MD; Leonard Abbeduto, PhD (UC Davis)

Children with Down syndrome (DS) have a 3-5 times greater prevalence of Attention Deficit Hyperactivity
Disorder (ADHD) than typically developing (TD) children. Despite this higher risk of ADHD, rates of stimulant medication treatment are disproportionately low in children with DS+ADHD, even though stimulants are the most efficacious ADHD treatment and are recommended by consensus guidelines for use in children with intellectual disability (ID) and comorbid ADHD. Possible reasons for under-utilization of stimulant treatment in DS+ADHD include: 1) diagnostic uncertainty regarding how to accurately diagnose ADHD in children with DS; making providers prone to “diagnostic overshadowing” (i.e., attributing ADHD to the ID); 2) there is not a single clinical trial examining the safety and efficacy of stimulant medication in children with DS+ADHD; and 3) concerns about cardiac safety, given the high incidence of congenital heart disease or defects (CHD) in the DS population.

We propose a pilot clinical trial to support the first randomized clinical trial (RCT) of stimulant medication in children with DS+ADHD. This future RCT may provide evidence regarding the short- and long-term safety and efficacy of stimulant use in children with DS+ADHD, both with and without CHD. The purpose of this pilot study is to inform sample size estimates for the larger clinical trial. All children enrolled in the study will complete a comprehensive assessment battery evaluating ADHD diagnostic criteria as well as behavioral, cognitive, academic, and functional impairments. Further, children will take part in the pilot methylphenidate (MPH) clinical trial to inform measures retained and desired sample size for the future clinical trial. The proposed study offers measurable milestones, to inform the clinical trial design, and an enhanced design that will address multiple research questions that, to date, have not been addressed in prior studies.