Getting too little sleep in early childhood is linked to cognitive and behavioural problems years later, a US study suggests.
Parents and teachers reported more problems in 7-year-olds who didn't get enough sleep during their toddler and preschool years, compared to peers who got an age-appropriate amount of sleep during those early years.
"Children who aren't getting the recommended amount of sleep have more difficulties with attention, with emotional control, with reasoning, with problem-solving, and also have behavioural problems," lead author Dr. Elsie Taveras told Reuters Health.
"What we found was that insufficient sleep in children was associated with poorer executive function and behaviour," said Taveras, who is chief of general pediatrics at Massachusetts General Hospital for Children in Boston.
Executive function is basically the brain's ability to process incoming information and respond to that information, Taveras said. "It's almost like your brain's functioning (as) air traffic control. Air traffic control has to know how to take in a bunch of information and how to process it."
Taveras and her colleagues analysed data on 1,046 children from a study that followed them from before birth. As part of the study, researchers had asked mothers how long the kids slept at age 6 months, 3 years and 7 years. The mothers also filled out health questionnaires every year.
Insufficient sleep was defined as less than 12 hours during infancy, less than 11 hours for 3- and 4-year-olds and less than 10 hours for 5- to 7-year-old kids.
Mothers and teachers were asked to evaluate each child's executive function and behaviour using questionnaires when the kids were 7 years old.
Children who slept less than 10 hours per day at ages 3 to 4 years had lower scores from both mothers and teachers compared to kids who usually slept longer. The results were similar for 5- to 7-year-olds who got less than 9 hours of sleep each night.
Sleep duration between 6 months and 2 years old was not linked to scores at age 7, according to the report in Academic Pediatrics.
Taveras said that being consistent with schedules and routines and setting age-appropriate bedtimes are important for good sleep.
"Don't have your child go to sleep at midnight on the weekends and then expect that you're going to be able to get them to bed and asleep by 8:30 on weekdays," she said.
Taveras also tells parents to get all the screens out of the kids' bedrooms including small devices that have push notifications or are beeping all night.
"(The study) adds to a building literature that is suggesting at least that having sleep problems early in life are predictive of behavioural and, in other populations, cognitive problems later," Dr. Dean Beebe told Reuters Health.
"And it is overall consistent with what we've seen in other studies in different age ranges," said Beebe, a pediatric neuropsychologist at Cincinnati Children's Hospital Medical Center who wasn't involved in the study.
"Having a parent do the sleep rating and then having both the parent and also a teacher do the behaviour ratings actually is a really big strength of the study," he added.
Beebe said he has three pieces of advice for parents. First, is to take a look and see what is the generally recommended amount of sleep for their kids by checking with the National Sleep Foundation (bit.ly/1Sy48EA) or the American Academy of Sleep Medicine (bit.ly/2mzoQa6).
"Number two is to pay attention to your child because some kids need more (sleep) and some kids need less," he said. The third thing is to establish a daily schedule that is sensitive to the child's needs, and also includes routines, Beebe said.
"The more chaotic and the less predictable that sleep schedule, the more difficulty the kids tend to have with sleep," he said.
The bedtime routine should involve a winding down period with relaxing activities such as reading a bedtime story, Beebe added. "It seems old fashioned but it's very calming, it's very connecting. It can be very soothing, and it's very predictable," he said.