Elementary school-age children who get less than nine hours of sleep per night have significant differences in certain brain regions responsible for memory, intelligence and well-being compared to children who get the recommended nine to 12 hours of sleep per night, according to a new study under led by researchers from the University of Maryland School of Medicine (UMSOM). Such differences correlated with greater mental health problems, such as depression, anxiety and impulsive behavior, in those who did not sleep. Insufficient sleep was also linked to cognitive problems with memory, problem solving and decision making. The findings are published today in the journal Lancet Child & Adolescent Health.
The American Academy of Sleep Medicine recommends that children ages 6 to 12 regularly sleep 9 to 12 hours a night to promote optimal health. To date, no research has been done on the long-term impact of insufficient sleep on the neurocognitive development of pre-teens.
To conduct the study, the researchers examined data collected from more than 8,300 children ages 9 to 10 who participated in the Adolescent Brain Cognitive Development (ABCD) study. They examined MRI images, medical records, and surveys completed by the participants and their parents at the time of enrollment and during a two-year follow-up visit at ages 11 to 12. The ABCD study, funded by the National Institutes of Health (NIH), is the largest long-term study of brain development and child health in the US.
We found that children who did not get enough sleep at the start of the study, less than nine hours a night, had less gray matter or volume in certain brain regions responsible for attention, memory and inhibition control compared to children with healthy sleeping habits. . These differences persisted after two years, a worrying finding that suggests long-term harm for those who don’t get enough sleep.”
Ze Wang, PhD, corresponding study author, professor of diagnostic radiology and nuclear medicine at UMSOM
This is one of the first findings demonstrating the possible long-term effects of sleep deprivation on neurocognitive development in children. It also provides substantial support for current sleep recommendations in children, according to Dr. Wang and his colleagues.
In follow-up assessments, the research team found that participants in the adequate sleep group tended to sleep gradually less over two years, which is normal as children enter their teens, while the sleep patterns of participants in the insufficient sleep group did not change much. The researchers controlled for socioeconomic status, gender, puberty status and other factors that can influence how much a child sleeps and affect the brain and cognition.
“We tried to match the two groups as closely as possible to help us better understand the long-term impact of too little sleep on the pre-adolescent brain,” said Dr. Cheek. “Additional studies are needed to confirm our finding and to see if interventions can improve sleep habits and reverse neurological deficits.”
The American Academy of Pediatrics encourages parents to promote good sleep habits in their children. Their tips include making getting enough sleep a family priority, sticking to a regular sleep routine, encouraging physical activity throughout the day, limiting screen time, and completely eliminating screens an hour before bed.
The study was funded by NIH. Fan Nils Yang, PhD, a postdoctoral researcher in Dr. Wang is a co-author of the study. Weizhen Xie, PhD, a researcher at the National Institute of Neurological Disorders and Stroke, is also a co-author on the study. UMSOM faculty members Thomas Ernst, PhD, and Linda Chang, MD, MS, are co-principal investigators of the ABCD study at the Baltimore site, but were not involved in the data analysis of this new study.
“This is a pivotal study that highlights the importance of long-term research into the developing child’s brain,” said E. Albert Reece, MD, PhD, MBA, Executive Vice President for Medical Affairs, UM Baltimore, and the John Z. and Akiko K. Bowers Distinguished Professor and Dean, University of Maryland School of Medicine. “Sleep can often be overlooked during busy childhood days filled with homework and extracurricular activities. Now we see how harmful that can be for a child’s development.”
University of Maryland School of Medicine