Modifications to weekend recovery sleep delay circadian phase in older adolescents.
Adolescents often report shorter time in bed and earlier wake-up times on school days compared to weekend days. Extending sleep on weekend nights may reflect a "recovery" process as youngsters try to compensate for an accumulated school-week sleep debt. The authors examined whether the circadian timing system of adolescents shifted after keeping a common late weekend "recovery" sleep schedule; it was hypothesized that a circadian phase delay shift would follow this later and longer weekend sleep. The second aim of this study was to test whether modifying sleep timing or light exposure on weekends while still providing recovery sleep can stabilize the circadian system. Two experiments addressed these aims. Experiment 1 was a 4-wk, within-subjects counterbalanced design comparing two weekend sleep schedule conditions, "TYPICAL" and "NAP." Compared to weeknights, participants retired 1.5 h later and woke 3 h later on TYPICAL weekends but 1 h later on NAP weekends, which also included a 2-h afternoon nap. Experiment 2 was a 2-wk, between-subjects design with two groups ("TYPICAL" or "LIGHT") that differed by weekend morning light exposure. TYPICAL and LIGHT groups followed the TYPICAL weekend schedule of Experiment 1, and the LIGHT group received 1 h of light (454-484 nm) upon weekend wake-up. Weekend time in bed was 1.5 h longer/night than weeknights in both experimental protocols. Participants slept at home during the study. Dim light melatonin onset (DLMO) phase was assessed in the laboratory before (Friday) and after (Sunday) each weekend. Participants were ages 15 to 17 yrs. Twelve participants (4 boys) were included in Experiment 1, and 33 (10 boys) were included in Experiment 2. DLMO phase delayed over TYPICAL weekends in Experiment 1 by (mean +/- SD) 45 +/- 31 min and Experiment 2 by 46 +/- 34 min. DLMO phase also delayed over NAP weekends (41 +/- 34 min) and did not differ from the TYPICAL condition of Experiment 1. DLMO phase delayed over LIGHT weekends (38 +/- 28 min) and did not differ from the TYPICAL group of Experiment 2. In summary, adolescents phase delay after keeping a commonly observed weekend sleep schedule. Waking earlier or exposure to short-wavelength light on weekend mornings, however, did not stabilize circadian timing in this sample of youngsters. These data inform chronotherapy interventions and underscore the need to test circadian phase-shifting responses to light in this age group.
Crowley
Stephanie J
SJ
Biological Rhythms Research Laboratory, Department of Behavioral Sciences, Rush University Medical Center, Chicago, Illinois 60612, USA. Stephanie_J_Crowley@rush.edu
Carskadon
Mary A
MA
D056044:Actigraphy; D000293:Adolescent; D001683:Biological Clocks / Q000502:physiology*; D002940:Circadian Rhythm / Q000502:physiology*; D005260:Female; D006706:Homeostasis; D006801:Humans; D008027:Light; D008550:Melatonin / Q000097:blood; D011897:Random Allocation; D012574:Schools; D012890:Sleep / Q000502:physiology*; D011795:Surveys and Questionnaires
D008550:Melatonin
Behav Sleep Med. 2005;3(3):113-33
15984914
J Sleep Res. 2007 Jun;16(2):163-9
17542946
J Biol Rhythms. 2005 Aug;20(4):353-65
16077154
Behav Sleep Med. 2003;1(2):102-14
15600132
J Clin Endocrinol Metab. 2001 Jan;86(1):433-6
11232036
Sleep. 2003 Mar 15;26(2):213-6
12683482
Chronobiol Int. 2002 Jul;19(4):695-707
12182497
Sleep. 2005 Nov;28(11):1446-54
16335485
Braz J Med Biol Res. 2008 Aug;41(8):734-8
18797710
Pediatrics. 2005 Jun;115(6):1555-61
15930216
Sleep. 2004 Feb 1;27(1):101-4
14998244
Sleep. 1994 Apr;17(3):201-7
7939118
Child Care Health Dev. 2008 Sep;34(5):549-56
18549435
Neurosci Lett. 2003 May 15;342(1-2):37-40
12727312
Neurosci Lett. 2004 Feb 12;356(2):115-8
14746877
Am J Physiol Regul Integr Comp Physiol. 2000 Feb;278(2):R373-82
10666138
J Sleep Res. 2005 Sep;14(3):229-37
16120097
Sleep. 2010 Jan;33(1):97-106
20120626
Ann N Y Acad Sci. 2004 Jun;1021:276-91
15251897
Pediatrician. 1990;17(1):5-12
2315238
Chronobiol Int. 2008 Nov;25(6):999-1016
19005901
J Pineal Res. 2005 Sep;39(2):195-200
16098098
Sleep. 2006 Dec;29(12):1632-41
17252895
Chronobiol Int. 2008 Jul;25(4):565-75
18622816
J Psychosom Res. 2002 Jul;53(1):529-37
12127168
J Sleep Res. 1995 Sep;4(3):173-182
10607156
J Physiol. 2003 Jun 15;549(Pt 3):945-52
12717008
Sleep. 2001 May 1;24(3):272-81
11322709
J Appl Psychol. 1989 Oct;74(5):728-38
2793773
J Biol Rhythms. 1997 Jun;12(3):278-89
9181439
J Sleep Res. 2002 Sep;11(3):191-9
12220314
Sleep. 2005 Dec;28(12):1561-7
16408416
J Neurosci. 2001 Aug 15;21(16):6405-12
11487664
J Neurosci. 1993 Mar;13(3):1065-79
8441003
J Physiol. 2001 Aug 15;535(Pt 1):261-7
11507175
Dev Neurosci. 2009;31(4):276-84
19546564
Pediatrics. 2005 Jan;115(1 Suppl):250-6
15866859
Chronobiol Int. 2009 Aug;26(6):1222-34
19731114
Sleep Med Rev. 2003 Dec;7(6):491-506
15018092
J Sleep Res. 2005 Sep;14(3):239-44
16120098
Percept Mot Skills. 2001 Aug;93(1):213-29
11693688
Sleep. 1980;2(4):453-60
7403744
Sleep. 1999 Feb 1;22(1):95-103
9989370
Science. 1989 Jun 16;244(4910):1328-33
2734611
Child Dev. 1998 Aug;69(4):875-87
9768476
J Investig Med. 1999 Mar;47(3):141-50
10198570