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Author Thorn, L.; Hucklebridge, F.; Esgate, A.; Evans, P.; Clow, A.
Title The effect of dawn simulation on the cortisol response to awakening in healthy participants Type Journal Article
Year 2004 Publication Psychoneuroendocrinology Abbreviated Journal Psychoneuroendocrinology
Volume 29 Issue 7 Pages 925-930
Keywords Human Health; Adult; Affect/*physiology/radiation effects; Arousal/*physiology/radiation effects; Circadian Rhythm/*physiology; Female; Humans; Hydrocortisone/analysis/*physiology/radiation effects; *Light; Male; Middle Aged; Reference Values; Saliva/chemistry; Wakefulness/*physiology/radiation effects
Abstract Bright light exposure after awakening has been shown to elevate cortisol levels in healthy participants. The present study examined the effect of dawn simulation (a treatment for seasonal affective disorder) on the cortisol response to awakening and mood. Twelve healthy participants were supplied with a dawn simulator (The Natural Alarm Clock, Outside In, Cambridge Ltd), a bedside light that increases in intensity prior to awakening to approximately 250 lux over 30 mins when an audible alarm sounds. A counterbalanced study was performed on 4 consecutive normal weekdays, two of which were control days (no dawn simulation) and two experimental (dawn simulation). Saliva samples were taken immediately on awakening then at 15, 30 and 45 minutes post awakening on all 4 study-days. Total cortisol production during the first 45 mins after awakening was found to be significantly higher in the experimental condition than in the control condition. Participants also reported greater arousal in the experimental condition and there was a trend for an association between increased arousal and increased cortisol secretory activity under dawn simulation. This study provides supportive evidence for the role of light and the suprachiasmatic nucleus in the awakening cortisol response.
Address Department of Psychology, University of Westminster, 309 Regent Street, London W1R 8AL, UK
Corporate Author Thesis
Publisher Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0306-4530 ISBN Medium
Area Expedition Conference (up)
Notes PMID:15177708 Approved no
Call Number LoNNe @ kagoburian @ Serial 824
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