Background: Hypersomnia of central origin from narcolepsy or idiopathic hypersomnia (IHS) is characterized by pathological levels of excessive daytime sleepiness (EDS). Central hypersomnia has historically been underdiagnosed and poorly understood, especially with respect to its impact on daytime functioning and quality of life in children. Objective: Describe the psychosocial adjustment of children treated for narcolepsy or IHS on school performance, quality of life, and physical/extracurricular activities. Methods: Using a matched case control design, we compared child self- and parent-reported data from thirtythree 8- to 16-year-olds with an established diagnosis of narcolepsy or IHS, according to ICSD-2 criteria, to that of 33 healthy children matched by age, race/ethnicity, gender, and household income. Assessments evaluated academic performance, quality of life and wellness, sleepiness, and participation in extracurricular activities. Results: Compared to healthy controls, children with central hypersomnia had poorer daytime functioning in multiple domains. Children with hypersomnia missed more days of school and had lower grades than healthy controls. Children with hypersomnia had poorer quality of life by both parent and child report. Children with hypersomnia were significantly sleepier, had higher BMI, and were more likely to report a history of recent injury. Finally, children with hypersomnia engaged in fewer after-school activities than healthy controls. Conclusions: A range of significant psychosocial consequences are reported in children with hypersomnia even after a diagnosis has been made and treatments initiated. Health care professionals should be mindful of the psychosocial problems that may present in children with hypersomnia over the course of treatment.