Investigators from the University of Maryland School of Medicine, Baltimore, MD, and the National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD, conducted a retrospective study to assess the effect of insufficient sleep on neurocognitive development and brain measures. For their study, they reviewed data that previously had been collected as part of the Adolescent Brain Cognitive Development (ABCD) study. ABCD is a longitudinal observational cohort study using a population-based sample of 9–10-year-old children enrolled at 21 sites in the US. Multiple instruments were administered at baseline and at the 2-year follow-up, including the Child Behavior Checklist, National Institutes of Health Cognition Battery Toolbox, and multiple questionnaires designed to measure mental health. In addition, functional and structural MRI scans were obtained on study participants at baseline and at the 2-year follow-up. Finally, sleep duration was assessed at each study time point based on parental responses on the Sleep Disturbance Scale for Children.
For the current analysis, children were classified as having sufficient sleep if their parent indicated that they generally slept ≥9 hours each night at the baseline visit, or insufficient sleep if they reportedly slept <9 hours on most nights. Using propensity score matching, participants with insufficient sleep were matched on a 1:1 basis with a participant with sufficient sleep. The propensity score was based on multiple child and parent demographic characteristics, pubertal status, BMI, and functional MRI quality indices. Differences at baseline on 42 behavioral items included in the neurocognitive tests were compared among those in the insufficient and sufficient sleep groups using t-tests. Correlations between results at baseline and at the 2-year follow-up were calculated to evaluate how stable the effects of insufficient sleep are over time. Similar procedures were used to compare differences in MRI findings at baseline between children in the 2 groups at baseline and the correlations between results at baseline and at the 2-year follow-up.
A total of 8,223 eligible participants were identified from the ABCD study, including 4,142 children in the sufficient sleep group and 4,181 with insufficient sleep. Using propensity scores, 3,021 participants with insufficient sleep were matched 1:1 to a child in the sufficient sleep group. At baseline, there were statistically significant differences between children in the 2 groups for 32 of the 42 behavioral assessments, and scores at baseline and 2-year follow-up were strongly correlated (r = 0.85; P <0.0001), suggesting insufficient sleep had stable effects on behavior over time. There also were significant differences between participants in the 2 groups for multiple MRI findings. At baseline, there were significant differences in 93 of 306 functional connections assessed, with moderate correlation over the 2-year study period (r = 0.54; P <0.0001), and significant differences...