background
Although the American Academy of Sleep Medicine suggests at least 9 hours of sleep per day for children between the ages of 6 and 12, children in recent generations often report sleeping less than this amount. Because early adolescence is a crucial period for neurocognitive development, we wanted to investigate how sleep deprivation affects children’s mental health, cognition, brain function, and brain structure over 2 years.
methods
In this observational, longitudinal, propensity cohort study, data were obtained from a population-based sample of 9- to 10-year-old children from 21 US study sites in the Adolescent Brain Cognitive Development Study ( ABCD) in progress. Participants were classified as sufficient or insufficient sleepers based on a sleep cutoff of 9 hours per day. Using propensity score matching, we matched these two groups of participants on 11 key covariates, including sex, socioeconomic status, and puberty status. Participants were excluded from our analysis if they did not pass a baseline resting-state functional MRI quality check or if data were missing for covariates involved in propensity score matching. Outcome measures obtained from the ABCD study were behavioral problems, mental health, cognition, and structural and functional measures of the brain at rest, assessed at baseline and 2-year follow-up. We examined group differences in these outcomes over these 2 years among all eligible participants. We then performed mediation analyzes of the neural correlates of sleep deprivation-induced behavioral changes.
discoveries
Between September 1, 2016 and October 15, 2018, 11,878 individuals had baseline data collected for the ABCD study, of whom 8,323 were eligible and included in this study (4,142 participants in the sufficient sleep and 4181 in the insufficient sleep group). Follow-up data were collected from July 30, 2018, to January 15, 2020. We identified 3,021 matched sufficient sleep–insufficient sleep pairs at baseline and 749 matched pairs at 2-year follow-up, and we observed similar differences between groups in behavioral and neural measures at both time points; effect sizes of between-group differences in behavioral measures at these two time points were significantly correlated with each other (r = 0·85, 95% CI 0·73–0·92; p<0·0001 ). A similar pattern was observed in resting state functional connectivity (r=0·54, 0·45–0·61; p<0·0001) and in structural measures (eg, in matter volume gray r=0·61, 0). ·51–0·69; p<0·0001). We found that functional cortico-basal ganglia connections mediate the effects of insufficient sleep on depression, thought problems, and crystallized intelligence, and that structural properties of the anterior temporal lobe mediate the effect of insufficient sleep on crystallized intelligence.
interpretation
These results provide population-level evidence of the lasting effect of insufficient sleep on neurocognitive development in early adolescence. These findings highlight the value of early sleep intervention to improve long-term developmental outcomes of early adolescents.
financing
National Institutes of Health.