Longitudinal EEG and Environmental Trajectories Leading to ADHD and Disruptive Behaviors from Infancy to Preschool - Project Summary Attention deficit hyperactivity disorder (ADHD) and disruptive behaviors (DBs) affect up to 9% of children. Under-diagnosis and under-treatment of ADHD and DBs disproportionately affect children with socioeconomic stress and disadvantage, and lead to early childhood morbidities (e.g., preschool expulsion, learning difficulties) and later adult adversity (e.g., mental health disorders, unemployment, suicide). Identification of infants and toddlers at risk for early ADHD and DBs, especially in families with socioeconomic disadvantage, would allow for provision of preventative interventions to minimize the negative impacts of these symptoms. Additionally, improved understanding of the neurodevelopmental pathways to ADHD and DBs would maximize the impact of developmentally and individually targeted preventative interventions. Accordingly, this study will leverage a large, currently enrolling NINDS funded sample of low-resourced, racially and ethnically diverse infants seen in an urban primary pediatric care clinic, for whom EEG, developmental and environmental data are already being collected longitudinally from 4- to 24-months old. The current investigation will collect EEG and ADHD/DB-focused measures at an additional time point (3- or 4-year well- child visit) in order to measure ADHD and DB outcomes in preschoolers. Our first aim is to characterize neurodevelopmental trajectories leading to early ADHD and DB symptoms using repeated EEG in very young children. Second, we will utilize parent survey data and medical record abstraction collected repeatedly across infancy and early childhood to integrate effects of social determinants of health (e.g., socioeconomic status, caregiver well-being, access to basic needs) into longitudinal models of brain development and behavioral regulation. Results from this study will inform future development of scalable and objective tools to identify children with increased likelihood of ADHD and DBs across resource settings, and facilitate development of interventions that use resources efficiently. Importantly, longitudinal characterization of this large cohort will provide greater understanding of what neurophysiological and environmental factors influence brain and behavioral development, and when the brain may be most sensitive to intervention.