Insomnia, adolescents and mental health - Bjørn Bjorvatn

Background/objective
Sleep is essential for health and well-being. However, several studies show that high school students have insufficient sleep and suffer from anxiety and depression. This invited lecture will present data from a large longitudinal cohort study among adolescents with focus on sleep, mental health, and registry-based school grades.

Methods
First-year high school students participated in a web-based survey. In total, 4863 students consented (response rate 42%). Two-year follow-up data were analyzed for 1456 (mental health) and 1092 (school grades) students.

Results
At baseline, we found that later school start times were associated with longer nighttime sleep duration, in a dose-dependent manner. Short school night sleep duration and insomnia symptoms (Bergen Insomnia Scale) at baseline predicted anxiety (GAD-7) and depression (PHQ-9) at two-year follow-up, even when adjusted for baseline levels of anxiety and depression. Furthermore, follow-up data showed that shorter school night sleep duration, more insomnia symptoms, and more depressive symptoms at baseline predicted worse grade point average (GPA) two years later. Baseline anxiety symptoms did not predict school grades at follow-up. These associations between sleep duration and insomnia symptoms on GPA remained significant also when adjusted for baseline symptoms of depression and anxiety.

Conclusions
These findings attest to the strong influence insufficient sleep has on mental health and cognitive functioning. Considering the high number of adolescents with short sleep duration and insomnia symptoms, it is imperative to target sleep to improve mental health and school performance during this vulnerable period of life (adolescence).