Caffeine effects on sleep taken 0, 3, or 6 hours before going to bed.
OBJECTIVE
Sleep hygiene recommendations are widely disseminated despite the fact that few systematic studies have investigated the empirical bases of sleep hygiene in the home environment. For example, studies have yet to investigate the relative effects of a given dose of caffeine administered at different times of day on subsequent sleep.


METHODS
This study compared the potential sleep disruptive effects of a fixed dose of caffeine (400 mg) administered at 0, 3, and 6 hours prior to habitual bedtime relative to a placebo on self-reported sleep in the home. Sleep disturbance was also monitored objectively using a validated portable sleep monitor.


RESULTS
Results demonstrated a moderate dose of caffeine at bedtime, 3 hours prior to bedtime, or 6 hours prior to bedtime each have significant effects on sleep disturbance relative to placebo (p < 0.05 for all).


CONCLUSIONS
The magnitude of reduction in total sleep time suggests that caffeine taken 6 hours before bedtime has important disruptive effects on sleep and provides empirical support for sleep hygiene recommendations to refrain from substantial caffeine use for a minimum of 6 hours prior to bedtime.
Sleep Disorders & Research Center, Henry Ford Hospital, Detroit, MI ; Department of Psychiatry and Behavioral Neurosciences, Wayne State College of Medicine, Detroit, MI.
Christopher
C
Drake
Timothy
T
Roehrs
John
J
Shambroom
Thomas
T
Roth
D000328:Adult; D000704:Analysis of Variance; D002110:Caffeine / Q000494:pharmacology*; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D008297:Male; D017286:Polysomnography / Q000187:drug effects / Q000379:methods; D012890:Sleep / Q000187:drug effects*; D013997:Time Factors; D014851:Wakefulness / Q000187:drug effects*
D002110:Caffeine
Caffeine; insomnia; sleep habits; sleep hygiene; stimulant