Kolla BP, et al. - Researchers conducted this investigation to analyze data on the prevalence and correlates of hypersomnolence symptoms. Participants in the study were 6,483 adolescents (aged 13 to 18 years) who were interviewed directly and had parent reports in the National Comorbidity Survey Replication Adolescent Supplement (NCS-A), a nationally representative sample of US youth. To study connections between sleepiness and sub-symptoms of hypersomnolence with weekday/weekend bedtime, sleep duration, mental disorders, and psychotropic medication use, logistic regression analyses were used. Data reported that hypersomnolence prevalence varied depending on age and was more common in adolescent girls. Of adolescents with a sufficient duration of sleep, 11.7% still reported hypersomnolence symptoms. The powerful link between hypersomnolence and insomnia indicates that adolescent sleep disorders may vary between over- and under-sleep. Potential mechanisms that underpin the powerful links between sleep disturbances and mental disorders should be pursued further and could provide insight into prevention attempts. Hypersomnolence was no longer related to the use of psychotropic medication after accounting for insomnia.