This research study is being conducted to look at oxygen as a treatment of obstructive sleep apnea (OSA) in children with Down syndrome. The main reason for the study is to show how 6 months of oxygen treatment while sleeping affects the participants sleep, quality of life, breathing, heart and if it makes the participant feel better.

This study wants to determine if racial differences in children that snore are related to factors that can be changed, such as child sleep habits, family factors, and provider unintentional racial bias. To accomplish this goal, we will compare measures of the sleepiness of children that snore and neurobehavioral impairments between Black and White children. We will also ask your child's healthcare provider to complete an implicit association test.

This research study aims to compare the accuracy of a home sleep apnea testing device (used as part of a home sleep study) for diagnosing obstructive sleep apnea in children who have had their adenoid and/or tonsils surgically removed, with an in-lab overnight sleep study. Children eligible for this study must be between the ages of 5 and 12. Participants will be randomly assigned to determine the order in which they complete the two sleep studies. After both the in-lab and home sleep studies are completed, families will be asked to complete questionnaires assessing the acceptability of home sleep apnea testing, as well as their preference between the two testing methods.

The purpose of this research is to compare home sleep apnea testing (HSAT) to in-lab overnight sleep study. We want to see if HSAT in children can be an alternative to in-lab sleep study for the diagnosis of obstructive sleep apnea.

The purpose of this research study is to see if melatonin improves sleep and the sleep-wake patterns (also known as circadian rhythm) in children, teenagers, and young adults (ages 11-30) with at-risk symptoms. Melatonin is naturally produced in the brain and controls sleep-wake patterns. At-risk symptoms can be feeling like you do not want to do be around other people as much, difficulties with focus, and having beliefs that most people around you don't have. At-risk symptoms can also be experiences like having jumbled up thoughts, your mind playing tricks on you, or seeing or hearing things that are not there. To see if melatonin changes sleep in youth with at-risk symptoms, we are giving some youth with at-risk symptoms a melatonin pill and some a placebo (a pill without any medication in it) for 6 months.