Sleeping through the ages: Developmental trajectories of actigraphy-derived sleep-wake patterns across adolescence...

Sleep is a fundamental domain of development and has important implications for other key aspects of adaptation. Little is known about normative changes in sleep across adolescence and emerging adulthood and whether the change is linear or nonlinear. We examined growth trajectories of sleep across 9 years of development and individual differences in trajectories according to participants' race/ethnicity and sex assigned at birth. During each wave, we measured four key actigraphy-derived sleep parameters over 1 week, including duration (number of minutes spent asleep), efficiency (percentage of time scored as sleep), midpoint (preferences for morningness-eveningness), and consistency/variability in duration (night-to-night fluctuations in duration over 1 week). Participants (N = 295, 53% female, 69% European American/White, 30% African American/Black, and 1% biracial) from diverse socioeconomic backgrounds completed five waves of data (M_ages at each wave: 15, 16, 17, 22, and 24). We observed a cubic trajectory for sleep duration whereby sleep duration declined across adolescence, increased into emerging adulthood, and declined again from 22 to 24. Consistency/variability in sleep duration also exhibited a cubic trajectory. Nightly fluctuations in sleep duration decreased from 15 to 16, increased from 16 to 22, and decreased again from 22 to 24. We found a quadratic trajectory for sleep midpoint, indicating a progressively greater preference for eveningness. Sleep efficiency exhibited linear growth and improved over time. Differences in trajectories for sleep duration and sleep efficiency emerged based on participants' race and sex. Findings indicated significant changes in the developmental trajectories of four sleep parameters across adolescence and emerging adulthood and underscore the importance of nonlinear assessments. (PsycInfo Database Record (c) 2026 APA, all rights reserved).