Abstract (summary): Background: Pediatric narcolepsy is a lifelong sleep disorder that is associated with depressive symptoms. The factors associated with depressive symptoms are unclear. Research on family functioning in pediatric narcolepsy is also limited. The primary objective of this study was to evaluate sleep and physical activity (PA) as factors associated with depression scores in adolescents with narcolepsy and controls. The secondary objective was to assess family functioning in pediatric narcolepsy Methods: Adolescents with narcolepsy and controls were recruited from the Hospital for Sick Children and Toronto area respectively. Participants wore an actigraph and pedometer to measure sleep and PA respectively. Depression scores were evaluated with the Children’s Depression Inventory-2. Family Functioning was assessed using the PedsQL Family Impact Module Results: Sixty adolescents (30 narcolepsy; 30 controls) participated. Poor sleep quality, excessive daytime sleepiness, and low PA levels were associated with greater depression scores. Family functioning was impaired in pediatric narcolepsy patients.