title: Daily timing of the adolescent sleep phase: Insights from a cross-species comparison.
abstract: Adolescence is a time of tremendous adjustment and includes changes in cognition, emotion, independence, social environment, and physiology. One of the most consistent changes exhibited by human adolescents is a dramatic delay in the daily timing of the sleep-wake cycle. This delay is strongly correlated with pubertal maturation and is believed to be influenced by gonadal hormone-induced changes in the neural mechanisms regulating sleep and/or circadian timing. Data from both human and non-human animals indicate that developmental changes in the intrinsic period of the circadian mechanism or its sensitivity to light are not adequate to explain adolescent changes in the daily timing of sleep and wakefulness. Rather, current evidence suggests that pubertal changes in the homeostatic drive to sleep and/or behaviorally induced changes in the amount and/or timing of light exposure permit adolescents to stay up later in the evening and cause them to wake up later in the morning.
authors.affiliation: Department of Psychology, Morehouse College, 830 Westview Dr. SW, Atlanta, GA, 30314, USA; Center for Behavioral Neuroscience, Georgia State University, Atlanta, GA, 30302-5090, USA. Electronic address: daniel.hummer@morehouse.edu.
authors.forename: Daniel L
authors.initials: DL
authors.lastname: Hummer
authors.affiliation: Department of Psychology, College of Arts and Sciences, The University of Tennessee, Knoxville, 312 Ayres Hall, 1403 Circle Drive, Knoxville, TN, 37996-1330, USA,. Electronic address: tlee35@utk.edu.
authors.forename: Theresa M
authors.initials: TM
authors.lastname: Lee
mesh_terms: D000293:Adolescent; D000375:Aging; D000818:Animals; D002940:Circadian Rhythm; D006706:Homeostasis; D006801:Humans; D012894:Sleep Stages; D014851:Wakefulness
keywords: Adolescence; Circadian period; Circadian phase; Development; Gonadal hormones; Phase delay; Puberty; SCN; Sex difference; Sleep pressure