Early morning melatonin administration impairs psychomotor vigilance.
The acute soporific effect of melatonin in humans has been demonstrated in a range of studies. How alertness and performance are changed after melatonin given in the morning is not yet known. In a double-blind, placebo-controlled study of nine healthy young men, melatonin was given at 0700 h under controlled conditions of a modified constant routine protocol lasting 56 h (2 days, 3 nights with sleep). A clear decrement in neurobehavioral functions as measured by the Psychomotor Vigilance Test lasted for 6 h after melatonin administration (particularly in the lapse domain and median of the reaction time) without any effect on a letter cancellation task. A subjective soporific effect was present but less pronounced. Thus, melatonin taken in the morning requires caution in situations where high attention is needed.
Graw
P
P
Centre for Chronobiology, Psychiatric University Clinic, Wilhelm Klein Strasse, 27, 4025 Basel, Switzerland. peter.graw@pukbasel.ch
Werth
E
E
Kräuchi
K
K
Gutzwiller
F
F
Cajochen
C
C
Wirz-Justice
A
A
D000328:Adult; D001288:Attention / Q000187:drug effects*; D002940:Circadian Rhythm / Q000187:drug effects*; D018592:Cross-Over Studies; D004311:Double-Blind Method; D004334:Drug Administration Schedule; D006801:Humans; D008297:Male; D008550:Melatonin / Q000008:administration & dosage*; D011597:Psychomotor Performance / Q000187:drug effects*; D011930:Reaction Time / Q000187:drug effects; D012890:Sleep / Q000187:drug effects; D014851:Wakefulness / Q000187:drug effects
D008550:Melatonin