Children with irregular bedtimes may be more prone to having behavioral problems, according to a new study.
Research published on Oct. 14 in Pediatrics showed that not going to bed at a regular time each night could interrupt a child's natural circadian rhythm, leading to lack of sleep. This in turn could affect how the brain matures and how kids are able to control certain behaviors.
"Not having fixed bedtimes, accompanied by a constant sense of flux, induces a state of body and mind akin to jet lag and this matters for healthy development and daily functioning," study author Yvonne Kelly, a professor at University College London Epidemiology & Public Health, said in a press release.
The National Sleep Foundation suggests that preschoolers between 3 and 5 years old get about 11 to 13 hours of sleep a night, while kids up to the age of 12 need around 10 to 11 hours of nightly shut-eye.
For the study, researchers looked at data from 10,230 7-year-olds who were enrolled in the U.K. Millennium Cohort Study. Data was collected from them at ages 3, 5 and 7, and their behavior was rated by their mothers and teachers.
Bedtime problems were most common at age 3, with one in five children going to bed a different time each night. About 9 percent of kids had irregular bedtimes when they were 5, and only 8.2 percent slept at different times each night by the time they turned 7 years old. By age 7, most of the kids regularly went to bed between 7:30 and 8:30 p.m.
Children who had irregular bedtimes or went to bed after 9 p.m. were more likely from socially-disadvantaged backgrounds.
Kids who went through early childhood without a set bedtime had more hyperactivity, conduct problems, problems with other people their age and emotional difficulties. Those who were put on a regular schedule had more improvements in these behavioral areas.
A previous study in the Journal of Epidemiology and Community Healthy showed that young girls with irregular bedtimes were more likely to have lower math, reading and special awareness scores by the age of 7 compared to those who went to bed at the same time each night.
Kelly pointed out that her study also found that behavioral problems could be improved upon if parents enacted a strict bedtime. Kids who switched to a set bedtime saw improvements in their behavior.
"As it appears the effects of inconsistent bedtimes are reversible, one way to try and prevent this would be for health care providers to check for sleep disruptions as part of routine health care visits," she said. "Given the importance of early childhood development on subsequent health, there may be knock-on effects across the life course. Therefore, there are clear opportunities for interventions aimed at supporting family routines that could have important lifelong impacts."