If you have not already done so, please read Blog Posts 1 through 5 that describe how sleep is important and beneficial. I will post specific information for parents and children based on my book, “Healthy Sleep Habits, Happy Child.” Please do not be put off by my book’s length. This is a reference book. Read only the topic of interest to you.
A 2022 report studied sleep, depression, and brain development in children at about 4.5, 10, 12, 13, 17, and 19 years of age. They measured the volume of gray matter of the brain (representing the concentration of the cell bodies of the nerves in the brain). There was an “interaction between bedtime and preschool depression severity, indicating that children with the earliest bedtimes and the lowest levels of depression showed the largest gray matter volume.” The authors correctly did not discuss this further because, in the context of multiple comparisons, the association did not reach statistical significance. However, the ‘bedtime’ was statistically significantly correlated with ‘sleep regularity’ and ‘total sleep duration (hours)’ such that children with early bedtimes had more sleep regularity and longer sleep durations.
I asked the lead author: Given the correlations between ‘bedtime’ and ‘sleep regularity’ and ‘total sleep hours’, how do you view the clinical importance of early as opposed to late bedtimes?
She responded: “Although not statistically significant, our findings indicated that children with earlier bedtimes and no depression symptoms showed larger total gray matter volumes across childhood and adolescence than children with late bedtimes (with or without depression symptoms). I think these results generally underscore the importance of early bedtimes in young children. We know exposures/experiences in early childhood can have a long term effects on neurodevelopment, and late bedtimes may be one pathway through which maladaptive neurodevelopment trajectories emerge.
For more information and sleep advice for children:
Blog Post 75 discusses how more sleep produces better mental health.
Blog post 123 reviews the benefits of early bedtimes.
Blog Post 127 summarizes the benefits from healthy sleep.