Adolescence, a time of transition fraught with physical, hormonal, emotional, and social changes is daunting for typically developing children. These challenges are magnified in children with autism. With 1 in 110 children being diagnosed with autism it is imperative to become proactive and begin to address the challenges these children may face in future years. Sleep problems are major health concerns in autistic children and it is expected that problematic sleep will extend into the adolescent and young adult years. Currently, there is little information available to help parents through this transition. This study aims to model the sleep behaviors in adolescents and young adults with autism and determine how sleep affects daytime behavior. The goals of this study are to characterize the sleep phenotype and its association with daytime sleepiness and problematic behaviors in adolescents/young adults with autism; and to define predictors and outcomes for future targeted interventions. It is hypothesized that delayed sleep phase, measured with actigraphy and serial melatonin, will be more predominant than insomnia in these individuals and greater than in age-gender matched typically developing individuals. The investigators use a multidimensional approach including sleep questionnaires and wrist actigraphy to characterize sleep behavior. Saliva will be collected to measure melatonin to model circadian patterns. Daytime behavior will be measured with standardized questionnaires. Understanding the sleep patterns of these individuals will allow to formulation of future treatments that target behavioral aspects of disturbed sleep, or determine specific pharmacological agents (e.g., melatonin) for future intervention studies. The long-range goal is to improve sleep and daytime behaviors in adolescents and young adults with autism.