Effect of Earlier Bedtime on Adolescent Sleep Duration

In adolescence, the sleep duration reduces by approximately 10 minutes each year. This change occurs due to a delay in the circadian rhythm and alterations in the regulation of sleep. 

A new study aimed to investigate whether teenagers can extend their sleep duration by preponing their bedtime and whether this ability changes with age.

The study involved two groups of participants. The younger cohort comprised 77 individuals aged between 9.9 and 16.2 years, who were observed annually for three years. The older cohort included 67 participants aged 15.0-20.6 years, who were studied only once. The participants were advised to follow three different time-in-bed (TIB) schedules (7, 8.5, and 10 hours) for four consecutive nights each year. The bedtime was adjusted earlier to modify the TIB. The sleep duration on the fourth night of each TIB schedule was measured by polysomnography.

Despite the increases in time to fall asleep and the time spent awake after falling asleep, the duration of sleep increased as the TIB advanced. On average, the sleep duration rose from 402.8 (1.6) minutes with 7 hours of TIB to 470.6 (2.1) minutes with 8.5 hours of TIB and further to 527.5 (3.0) minutes with 10 hours of TIB. Notably, the sleep duration decreased with age at a rate of 1.55 (0.48) minutes per year, yet, the effect of TIB on sleep duration remained consistent – showing no significant change with age. 

The findings indicate that adolescents can significantly increase their sleep duration by going to bed earlier, and this ability remains constant between the ages of 10 and 21 years. Further research is necessary to understand how these results can be translated from controlled experimental sleep schedules to actual increases in sleep duration in real-world scenarios. The results provide valuable insights into adolescent sleep. The observed increase in sleep duration due to advancing bedtime supports previous studies suggesting that teenagers with parent-set bedtimes experience longer sleep durations. Moreover, encouraging earlier bedtimes for adolescents seems more effective than discrediting them. 

Although previous studies on sleep education programs have not shown lasting increases in sleep duration or increased sleep knowledge without a corresponding increase in sleep duration, the current findings support the effectiveness of advancing bedtime. The practical application in real-life situations needs further investigation.

Source: Campbell IG, Cruz-Basilio A, Figueroa JG, et al. Pediatrics. 2023 Jun 12:e2022060607.