We know about the benefits of regular and long enough sleep in babies: strengthening memory, growth, development of creativity … But this time, a recent study published in The Lancet Child & Adolescent Health studied the long-term effects of lack of sleep in children. It identifies cognitive difficulties (memory, problem solving and decision making), mental problems and gray matter deficiency in certain areas of the brain.
This study was conducted on over 8,000 children.
This is one of the first large-scale studies of the effects of poor sleep in the youngest, in a cohort of more than 8,300 children aged 9 to 10, over a period of two years. They were divided into 2 groups. One included all those who slept an average of 9 hours a day or more, and the other included children who slept less than 9 hours. The sleep threshold of 9 hours a night is indeed considered the minimum required for optimal health in children ages 6 to 12, according to the American Academy of Sleep Medicine.
The researchers rely on another animal study published in Frontiers to support their hypothesis: “Lack of sleep may have long-term negative effects on participants’ neurocognitive development.” To evaluate this influence, the University of Maryland School of Medicine looked at various factors in each of the children: their possible behavioral problems, their cognitive difficulties, their mental health… They even took measurements of their brain, both its structure and functional connections. To this end, researchers are using MRI scans, medical records, and interviews with families to ascertain the effects of too short nights in toddlers.
We know about the benefits of regular and long enough sleep in babies: strengthening memory, growth, development of creativity … But this time, a recent study published in The Lancet Child & Adolescent Health studied the long-term effects of lack of sleep in children. It identifies cognitive difficulties (memory, problem solving and decision making), mental problems and gray matter deficiency in certain areas of the brain.
This study was conducted on over 8,000 children.
This is one of the first large-scale studies of the effects of poor sleep in the youngest, in a cohort of more than 8,300 children aged 9 to 10, over a period of two years. They were divided into 2 groups. One included all those who slept an average of 9 hours a day or more, and the other included children who slept less than 9 hours. The sleep threshold of 9 hours a night is indeed considered the minimum required for optimal health in children ages 6 to 12, according to the American Academy of Sleep Medicine.
The researchers rely on another animal study published in Frontiers to support their hypothesis: “Lack of sleep may have long-term negative effects on participants’ neurocognitive development.” To evaluate this influence, the University of Maryland School of Medicine looked at various factors in each of the children: their possible behavioral problems, their cognitive difficulties, their mental health… They even took measurements of their brain, both its structure and functional connections. To this end, researchers are using MRI scans, medical records, and interviews with families to ascertain the effects of too short nights in toddlers.
“We found that children who were awake at the start of the study had less gray matter or less volume in certain areas of the brain involved in attention, memory, and inhibitory control, compared to those who had healthy sleep.”
Credit: University of Maryland School of Medicine.
Two mechanisms have been identified
By comparing the functional associations of the two groups, the researchers realized that sleep-deprived children had fewer of them. Cause? Short nights disrupt the ganglia at the base of the brain, resulting in poor information processing. Thus, children who lack sleep will be more prone to behavioral disorders (impulsivity, depression, anxiety, etc.). At the same time, cognitive and affective functions change.
The second mechanism affects what is called “crystallized intelligence”, that is, the ability to use accumulated experience and knowledge. Through structural measurements of the temporal lobe, the researchers identified a gray matter deficit in this region of the brain. The maturation of the temporal lobe in sleepless children is delayed, which disrupts the consolidation of their memory and therefore their “crystallized intelligence”.
In fact, several factors can influence sleep. The researchers identified 11 different variables, including gender, puberty and parental socioeconomic status. “For example, a child’s sleep duration and household income are often closely related.” These factors may have skewed the results of the study. Therefore, the researchers decided to eliminate these variables by comparing children in pairs with similar characteristics. sleeping less than 9 hours was compared with another person sleeping more than 9 hours and whose gender, puberty and socioeconomic status were the same or similar. In this way, scientists were able to isolate and identify the direct effects of sleep deprivation on their brains.
Permanent effects
Poor memory, difficulty solving problems and making decisions – the consequences are numerous and affect both thinking and behavior. Even more troubling, research shows persistence of these symptoms over time. Follow-up visits over 2 years allowed researchers to identify persistent behavioral and cognitive problems in sleep-deprived participants early in the study. These disorders can range from impulsive attitudes to depression through anxiety and malaise.
However, the question of the reversibility of the effects remains unresolved: can the resumption of healthy habits reverse the neurological deficit?
Beware of too long nights
Set fixed bedtimes and wakeup times, set a bedtime routine, limit screen time… All of these habits are recommended by Santé Publique France to improve sleep quality for babies. .
The Sleep and Vigilance Institute recommends about 10 hours of sleep for children around the age of ten. The exact duration depends on each person. Criteria to judge if the night was long enough? “The child should get up in a good mood,” says Public Health France. If he hasn’t slept enough, he will be irritable and less focused than usual. Facilitating natural awakening to the rhythm of the sounds of the house also contributes to its well-being.
This American study proves that 9 hours of sleep or more contributes to good neurocognitive development. On the other hand, the researchers warn: “These results do not in any way suggest that the more sleep we get, the better our health!” Indeed, nights that are too long can also affect mental health.