Sleep, Brain Development, and Behavioral Correlates in a Longitudinal Cohort of Children at Risk for ASD - PROJECT SUMMARY Title: Sleep, Brain Development, and Behavioral Correlates in a Longitudinal Cohort of Children at Risk for ASD Children with autism spectrum disorder (ASD) are 2-3 times more likely to suffer from sleep problems than typically developing children. Despite being a high priority population for sleep research, and despite evidence that sleep problems have pervasive negative consequences for health, behavior, mood, and cognition, the increased occurrence and clinical impact of sleep problems in individuals with a family history of ASD is not well understood. This major public health concern is the focus of our application, “Sleep, Brain Development, and Behavioral Correlates in a Longitudinal Cohort of Children at High-Risk for ASD”. Problems with sleep initiation, circadian timing, and inadequate amount of sleep in a high familial risk (HR) cohort of school-age children are hypothesized to be preceded by altered brain and behavioral development in early childhood. This proposal leverages a recently funded longitudinal follow-up of school-age (7-12-year-old) HR children and children with low familial risk for ASD (LR) who have had multiple MRI and behavior assessments since infancy through the NIH Autism Center of Excellence Infant Brain Imaging Study (IBIS). This sample of 300 HR children includes ~100 diagnosed with ASD at 24 months, ~200 without a diagnosis of ASD but with outcomes ranging from typical development to developmental and psychiatric disorders known to occur at high rates in siblings of children with ASD, and 100 LR children currently returning for assessment, including MRI, during school age. A biopsychosocial model of pediatric sleep problems predicts that some combination of biological, environmental, behavioral and psychiatric factors will account for the increased prevalence of sleep problems in ASD, but it is unknown whether sleep problems are familial, endophenotypic, or disorder- specific in this population. We propose to: (1) characterize circadian disturbances, sleep duration, and other sleep parameters in the home using actigraphy, validated by sleep diary, and through parent report of behavioral and medical sleep problems, (2) examine brain growth trajectories (from infancy) associated with sleep problems in school-age, and (3) examine the longitudinal behavioral and developmental trajectories and concurrent behavior associated with sleep problems in school-age. Increased understanding of the neurobiology and developmental characteristics of sleep problems in ASD has important implications for developing novel, developmentally-sensitive sleep interventions which may help to reduce behavioral and health problems exacerbated by sleep problems and improve outcomes in this vulnerable population.