Age-Related Differences in Sleep Architecture and Electroencephalogram in Adolescents in the National Consortium on Alcohol and Neurodevelopment in Adolescence Sample

To investigate age-related differences in polysomnographic and sleep electroencephalographic (EEG) measures, considering sex, pubertal stage, ethnicity, and scalp topography in a large group of adolescents in the National Consortium on Alcohol and NeuroDevelopment in Adolescence (NCANDA). Following an adaptation/clinical screening night, 141 healthy adolescents (12–21 y, 64 girls) had polysomnographic recordings, from which sleep staging and EEG measures were derived. The setting was the SRI International Human Sleep Laboratory and University of Pittsburgh Pediatric Sleep Laboratory. Older age was associated with a lower percentage of N3 sleep, accompanied by higher percentages of N2, N1, and rapid eye movement (REM) sleep. Older boys compared with younger boys had more frequent awakenings and wakefulness after sleep onset, effects that were absent in girls. Delta (0.3–4 Hz) EEG power in nonrapid eye movement NREM sleep was lower in older than younger adolescents at all electrode sites, with steeper slopes of decline over the occipital scalp. EEG power in higher frequency bands was also lower in older adolescents than younger adolescents, with equal effects across electrodes. Percent delta power in the first NREM period was similar across age. African Americans had lower EEG power across frequency bands (delta to sigma) compared with Caucasians. Finally, replacing age with pubertal status in the models showed similar relationships. Substantial differences in sleep architecture and EEG were evident across adolescence in this large group, with sex modifying some relationships. Establishment and follow-up of this cohort allows the investigation of sleep EEG-brain structural relationships and the effect of behaviors, such as alcohol and substance use, on sleep EEG maturation. Data presented here from a large sample of male and female adolescents show substantial age-related differences in sleep architecture and electroencephalogram across this critical period of development. Age effects were generally larger for boys, who showed more disturbed sleep architecture at an older age, than girls. There is a substantial age-related decline in delta power, which is evident across the scalp, particularly in the occipital region. However, there was no age difference in percent delta power in the first nonrapid eye movement period, suggesting stability of homeostatic sleep mechanisms across adolescence. Longitudinal tracking of this cohort will allow investigation of age-related changes in sleep in conjunction with structural brain changes, as well as how adolescent behaviors affect maturation of the sleep electroencephalogram.