Lasting consequences: A study shows that when elementary school children are consistently underslept, it has a lasting impact on their brains and mental development. According to the study, children who slept less than nine hours a night had less gray matter in brain areas involved in attention, impulse control and memory. In addition, they were more likely to have behavioral problems and cognitive deficits. These differences could still be detected two years later.
Sleep is essential for our brain. During this resting period, waste is flushed out, memory is sorted and synapses are recalibrated. If we don’t sleep, we become more irritable, more sensitive to pain, have difficulty concentrating and tend to have distorted memories. Studies also suggest that prolonged lack of sleep also increases the risk of cardiovascular disease and can even destroy brain cells.
Lack of sleep is particularly harmful to children. Because their still developing brain needs the nightly rest break even more urgently than in adults. Sleep doctors therefore recommend that children of primary school age should get at least nine hours of sleep.
Primary school children in a comparative test
But what happens when children constantly get too little sleep? Fan Nils Yang from the University of Maryland in Baltimore and his colleagues have now investigated this in more detail. To do this, they evaluated data from 8,323 girls and boys who were nine to ten years old when the study began. By surveying the parents, the researchers determined how long the children slept on average each night.
All children were psychologically and medically examined at baseline and again two years later, and their cognitive performance was tested. The team also examined the children’s brain anatomy and function using functional magnetic resonance imaging at baseline and after two years. For the evaluation, children with and without enough sleep were compared in pairs in such a way that their background and living conditions were as similar as possible.
“We tried to match the two groups as best we could so that we could better understand how sleep deprivation affects the preadolescent brain in the long term,” says Yang’s colleague Ze Wan,
Less gray matter and cognitive deficits
The result: “We found that children who slept less than nine hours a night had less gray matter and a smaller volume in certain brain areas than children who got enough sleep,” reports Wang. “The affected areas of the brain are responsible for attention, memory and impulse control.” These included, among other things, parts of the cerebral cortex in the temporal lobe. At the same time, there were also differences in the functional connections between different brain areas.
However, the consequences of the lack of sleep were also reflected in the children’s behavior and cognitive abilities: In tests of memory, problem-solving skills and decision-making ability, children with less than nine hours of sleep performed worse than their better abilities. rested peers. Also, impulsive behavior, depression or anxiety were more common in these children than in those who regularly got more than nine hours of sleep.
“These differences were also still detectable two years later—a worrisome finding because it suggests long-term damage in children who don’t get enough sleep,” says Wang.
It must be at least nine hours
Sleep doctors recommend a night’s sleep of at least nine hours for children between the ages of nine and twelve. “But in the hectic everyday life between schoolwork and extracurricular activities, it can quickly get lost,” says co-author Albert Reece of the University of Maryland. The use of computers, tablets and mobile phones in the evening also contributes to children’s ever-shorter sleep time.
“But now we’re seeing how damaging it can be to a child’s development,” Reece said. According to the researchers, their findings confirm that adequate sleep is important for children’s brain development – and how harmful a persistent lack of sleep can be. (The Lancet Child & Adolescent Health, 2022; doi: 10.1016/S2352-4642(22)00188-2)
Source: University of Maryland School of Medicine