A process-oriented model linking adolescents' sleep hygiene and psychological functioning: the moderating role of school start times.

OBJECTIVE

To examine a mediational model linking sleep hygiene to better mental health in adolescents via the mechanism of improved sleep quality, and to test the moderating role of school start times (SST) (before 8:30 AM vs. 8:30 AM or later) on that mediation model.

DESIGN

Cross-sectional.

SETTING

Online survey for high school students across the United States.

PARTICIPANTS

A total of 197 adolescents aged 14-17 years old (M = 15.6 years, SD = 1.8; 53% female) completed a baseline survey and 7-day sleep diaries; their parents (M = 47.7 years, SD = 5.5; 79% female) reported on family socioeconomic status and high SST.

MEASUREMENT

Adolescents reported on their sleep hygiene, circadian chronotype, daily levels of sleep quality and duration (morning diaries) and their depressive/anxiety symptoms (evening diaries) for 7 days.

RESULTS

A moderated-mediation model suggested that baseline sleep hygiene was directly associated with lower average daily depressive/anxiety symptoms across all students, but that association was marginally stronger in students with later SST (8:30 AM or later). A mediated path emerged only for students with earlier start times, suggesting that, for those students, baseline sleep hygiene was indirectly associated with lower average daily psychological symptoms by improving average daily sleep quality.

CONCLUSIONS

The current study is one of the first to demonstrate that SST might serve as a critical moderator in models of adolescent sleep and daily functioning. The findings provide additional evidence in the debate on how SST may affect adolescent health.