Mapping Primary Outcome Domains in Pharmacological Trials for Children with Neurodevelopmental Disabilities: A Cross-sectional, Registry-based Landscape Analysis of ClinicalTrials.gov

Abstract

Neurodevelopmental disabilities (NDDs) are among the most common chronic childhood conditions and are frequently managed pharmacologically. However, the outcome measures used in clinical trials may not adequately capture treatment effects that are meaningful to affected children and their families. This cross-sectional registry-based landscape analysis identified completed interventional drug trials in pediatric NDDs from ClinicalTrials.gov using publicly available data retrieved on July 8, 2026. Primary outcome measures were classified into pre-specified domains and analyzed using descriptive statistics. After applying the eligibility criteria, 706 completed pharmacological trials involving 74,299 participants were included. Research activity was concentrated in a small number of conditions, with attention-deficit/hyperactivity disorder (43.5%) and autism spectrum disorder (25.5%) accounting for most trials, whereas rare conditions such as Williams and Smith–Magenis syndromes were represented by very few studies. Among the 683 trials with a classifiable primary outcome, symptom-based measures predominated (55.3%), while person-centered outcomes reflecting lived experience, well-being, autonomy, or participation were the primary endpoint in only 1.0% of trials. Results were publicly available for approximately half of the completed trials (50.6%). Overall, pharmacological research in pediatric NDDs remains centered on symptom-based endpoints, whereas person-centered outcomes are rarely selected as primary measures. These findings highlight an important gap between emerging recommendations for person-centered research and current trial practice and provide a benchmark for future efforts to broaden outcome selection where appropriate.