Tokiya M, Itani O, Otsuka Y, et al. - Researchers conducted this cross-sectional study to explore the connection between sleep disturbance in adolescents and Internet addiction (IA), defined as “an impulse-control disorder that does not involve an intoxicant”, based on the categories of the Young Diagnostic Questionnaire (YDQ) in one prefecture in Japan. In 2016, high school students (N = 10,405, age range: 15–16 years) were surveyed using a self-administered questionnaire in all 54 daytime high schools in the selected prefecture. Candidates with scores > 5.5 points on the Japanese version of the Pittsburgh Sleep Quality Index were defined as having a sleep disturbance. Findings suggested an association of high YDQ scores with a high prevalence of sleep disturbance in boys and girls. Such results persisted in the multiple regression model despite accounting for other variables. There has been a significant independent relationship between the IA and sleep disturbance among Japanese adolescents.