Long-lasting effects of insufficient sleep on neurocognitive development in early adolescence
Authors: Yang Fan Nils , Xie Weizhen , Wang Ze 
Published: January 2022

AbstractImportanceAdolescents nowadays often get insufficient sleep. Yet, the long-term adverse effects of sleep loss on developing brain and behavior remains unknown.ObjectiveTo determine whether insufficient sleep leads to long-lasting impacts on mental health, cognition, and brain development in adolescents across two years.DesignThis longitudinal study utilized a public dataset, the Adolescent Brain Cognitive Development (ABCD) study, which is an ongoing study starting from 2016.SettingData were collected from 21 research sites in the U.S.Participants11,875 9-10-year-olds were recruited using stratified sampling in order to reflect the diversity of the U.S. population.InterventionIndividuals with sufficient versus insufficient sleep (< 9 hours per day for adolescents) were compared after controlling for age (months), sex, race, puberty status, and other 7 covariates based on propensity score matching.Main Outcomes and MeasuresBehavior problems, cognition, mental health assessments, resting-state functional connectivity, gray matter volume, cortical area, cortical thickness, and structural connectivity (Fractional anisotropy) were collected and preprocessed by the ABCD study. Independent-sample t-tests and meditation analysis were performed to investigate the effects of insufficient sleep.Results3021 matched pairs (50.7% male) were identified based on baseline assessment, with mean (SD) age of 119.5 (7.5) months. In baseline, sufficient sleep is associated less behavioral problems on 18 of 20 assessments, e.g. depress (95% CI of mean difference: -0.28 to -0.47, false discovery rate (FDR)-corrected p□<□.001, Cohen’s d = -0.20), better cognitive performance on 7 of 10 assessments, such as crystal cognition (95% CI: 0.81 to 1.50, FDR-corrected p□<□.001, Cohen’s d = 0.17), better functional connection between cortical regions and basal ganglia (all FDR-corrected p□<□.05, Cohen’s d >0.15), and large structure in ACC and temporal pole (all FDR-corrected p□<□.05, Cohen’s d >0.09). Similar patterns of effect of sufficient sleep were found in FL2 (749 pairs remained) e.g. Cohen’s d of function connectivity at baseline was correlated with Cohen’s d of that at FL2 (r = 0.54, 95% CI: 0.45 to 0.61, p < 1e-10). Mediation and longitudinal mediation analysis revealed that identified brain measures (e.g. gray matter volume of left temporal pole) at baseline mediated the effect of sufficient sleep on behavioral assessments (e.g. crystal cognition) at baseline and at FL2 (95% CI did not encompass 0, p < 0.05 on 100,000 random-generated bootstrapped samples).Conclusions and RelevanceThese results provide strong population-level evidence for the long-lasting detrimental effects of insufficient sleep on mental health, cognition, and brain function and structure in adolescents. The current study identified potential neural mechanisms of adverse effect of insufficient sleep in adolescents, which might provide a theoretical grounding for sleep intervention programs to improve the long-term developmental outcomes in adolescents.Key pointsQuestionWhat are the long-lasting effects of insufficient sleep on neurocognitive development in early adolescents?FindingsIn this propensity score matching study that included 11,875 9-10-year-old participants, we identified long-lasting adverse effects of insufficient sleep on depression, thought problems, crystal cognition, neural network connectivity, cortical areas, and gray matter volume across 2 years.MeaningThis study elucidated the neural mechanisms underlying the long-term detriments of insufficient sleep on mental health and cognition, suggesting potential intervention targets to improve sleep-related outcomes.