Trajectory Moderators of Functional Outcomes and ADHD Symptoms in Children With ADHD.

Objective: ADHD can impair children's functioning. Socioeconomic and sociodemographic factors present barriers to treatment access and lead to disparate outcomes in children with ADHD. The purpose of this study was to describe trajectories of functional outcomes and ADHD symptom counts across 3 years and explore the moderating effects of income and race/ethnicity on these trajectories among U.S. children with ADHD.

Method: This longitudinal study of children currently and/or previously meeting diagnostic criteria for ADHD (N = 1,587, age = 9-10 years at baseline) used data from the Adolescent Brain Cognitive Development (ABCD) Study^®. Outcomes were child-reported functional outcome measures (family conflict, prosocial behavior, and school experiences) and parent-reported inattentive and hyperactive symptom counts across 3 years. Multi-level, mixed-effects models for longitudinal data were used to characterize each outcome trajectory and examine the moderating effects of baseline household income and race/ethnicity.

Results: The sample was 68% male and 54% White, with 53% meeting diagnostic criteria for past-only ADHD, 12% current-only ADHD, and 35% both past and current ADHD. Significant changes in family conflict, school experiences, inattentive symptom counts, and hyperactive symptom counts were demonstrated across 3 years (trajectories, p < .05). Income significantly moderated prosocial behavior trajectories, while race/ethnicity significantly moderated family conflict and prosocial behavior trajectories (time interaction, p < .05).

Conclusions: The findings suggest that factors related to income and race/ethnicity influence trajectories of change in family conflict and prosocial behavior outcomes in children with a history of ADHD. Future studies should explore these disparities and identify targets for intervention, such as increased access to diagnosis and treatment for individuals at risk of poorer functional outcomes.