Sleep Quality in Korean High School Students Is Associated With Lower Social Jetlag, Longer Weekday Time in Bed, and Less Self-Suppressive Defense Style

Objective: Good sleep in adolescents may influence brain development and psychological problems such as anxiety and depression. Although social jetlag has been associated with sleep quality in adolescents, the association between other behavioral and personality factors and sleep quality in adolescents has not been elucidated. Methods: Sleep-related behaviors, such as time in bed (TIB) on weekdays and weekends, social jetlag, and daytime sunlight exposure, were evaluated using various measurement tools such as sleep-related questionnaires, including defense style and morningness–eveningness questionnaires, insomnia severity index, Epworth Sleepiness Scale, and hospital anxiety and depression scale. This study involved 1,610 high school students. Results: Multiple linear regression analysis revealed an association of better sleep quality with lesser social jetlag (β=0.085, t=3.217, p=0.001) and longer weekday TIB (β=-0.072, t=-2.634, p=0.009) after adjusting for age, sex, anxiety, depression, daytime sleepiness, weekday total sleep time, weekend oversleep, and mean daily sunlight exposure time. Furthermore, better sleep quality in adolescents was associated with lesser self-suppressive defense style (β=0.097, t=4.094, p<0.001) after adjusting for age, sex, anxiety, depression, chronotype, and daytime sleepiness. Conclusion: Good sleep quality in adolescents may be related to behavioral factors, such as lower social jetlag and longer weekday TIB, and psychological factors, such as a less self-suppressive defense style.