In a propensity score matched, longitudinal, observational cohort study, findings showed that there was an association between insomnia and neurocognitive function in children.
Recently, findings from the Adolescent Brain Cognitive Development (ABCD) study, including more than 8300 children aged 9 to 10 years, showed an association in the duration of less sleep and difficulties with neurocognitive development.1 This finding provides population-level evidence on early adolescence on the impact that insufficient sleep has on neurocognitive development. The results also focus on the attention of promoting sleep interventions with the aim to improve the long-term developmental outcomes of children.2
Between the groups of insufficient sleepers and sufficient sleeps, there were similar differences observed in behavior and neural measures at both study timepoints of baseline and 2-year follow-up. The 2 study time points were significantly associated with each other in behavioral measures for the effect sizes of the between-group differences (r = 0.85; 95% CI, 0.73-0.92; P <.0001). There have not been any studies done previously on the impact that insufficient sleep has over time for the neurocognitive development of children.2
"This is a crucial study finding that points to the importance of doing long-term studies on the developing child's brain," E. Albert Reece, MD, PhD, MBA, executive vice president for medical affairs, University of Maryland, Baltimore, said in a statement.2 "Sleep can often be overlooked during busy childhood days filled with homework and extracurricular activities. Now we see how detrimental that can be to a child's development."
Data for the study came from a population-based sample of 9- to 10-year-olds from 21 study sites across the United States. Baseline data from 11,878 individuals were collected between Sept 1, 2016, and Oct 15, 2018, of whom 8323 were eligible and participated in the study. There were 2 groups that the participants were split into, one made up of those with sufficient sleep (n = 41420) and the other group consisted of individuals who had insufficient sleep (n = 4181). From July 30, 2018, to Jan 15, 2020, the follow-up data were collected.
The researchers then matched the groups, using a propensity score matching, on 11 key covariates. The covariates consisted of socioeconomic status, gender, puberty status, and other factors that could affect how much a child sleeps and affect brain and cognition.2 If participants did not pass a baseline MRI quality check or had missing data of the covariates, they were excluded from the analysis.
"We found that children who had insufficient sleep, less than 9 hours per night, at the beginning of the study had less grey matter or smaller volume in certain areas of the brain responsible for attention, memory and inhibition control compared to those with healthy sleep habits," coauthor Ze Wang, PhD, professor of diagnostic radiology and nuclear medicine, University of Maryland School of Medicine, said in a statement.2 "These differences persisted after two years, a concerning finding that suggests long term harm for those who do not get enough sleep.”
Behavioral problems, mental health, cognition, and structural and resting-state functional brain measures were the outcome measures that were assessed at the baseline and at the 2-year follow-up. The researchers examined the outcomes among the participants to make out the group differences over the course of the 2 years and then performed, a “mediation analyses of the neural correlates of behavioral changes induced by insufficient sleep.”1 At the baseline, there were 3021 matched sufficient sleep–insufficient sleep pairs identified whereas at the 2-year follow-up, there were 749 matched pairs.
Other findings from the study showed that corticobasal ganglia functional connections mediated the effects of insufficient sleep on depression, thought problems, and crystallized intelligence. In addition, the structural properties of the anterior temporal lobe mediated the effect of insufficient sleep on crystallized intelligence.
Notably, there was also an association with resting-state functional connectivity (r = 0.54; 95% CI,0.45–0.61; P <.0001) and in structural measures (eg, in grey matter volume, r = 0.61; 95% CI, 0.51-0.69; P <.0001) between the groups.1 The follow-up assessment showed that the sleep patterns of the participants in the insufficient sleep group did not change much in comparison with the participants in the sufficient sleep group who gradually slept less over the course of the two years of the study.2
"We tried to match the 2 groups as closely as possible to help us more fully understand the long-term impact on too little sleep on the preadolescent brain," Wang said in a statement.2 "Additional studies are needed to confirm our finding and to see whether any interventions can improve sleep habits and reverse the neurological deficits."
According to Wang and colleagues, this study supports the need to promote sleep recommendations for children to parents. Possible recommendation for healthy sleeping habits for children, suggested by the American Academy of Pediatrics, include making sleep a, “family priority, sticking with a regular sleep routine, encouraging physical activity during the day, limiting screen time and eliminating screens completely an hour before bed.”2