title: Zeitgeber hierarchy in humans: resetting the circadian phase positions of blind people using melatonin.
abstract: Four blind individuals who were thought to be entrained at an abnormal circadian phase position were reset to a more normal phase using exogenous melatonin administration. In one instance, circadian phase was shifted later. A fifth subject who was thought to be entrained was monitored over four years and eventually was shown to have a circadian period different from 24 h. These findings have implications for treating circadian phase abnormalities in the blind, for distinguishing between abnormally entrained and free-running blind individuals, and for informing the debate over zeitgeber hierarchy in humans.
authors.affiliation: Sleep and Mood Disorders Laboratory, Department of Psychiatry, Oregon Health & Science University, Portland, Oregon, USA. lewy@ohsu.edu
authors.forename: Alfred J
authors.initials: AJ
authors.lastname: Lewy
authors.forename: Jonathan
authors.initials: J
authors.lastname: Emens
authors.forename: Robert L
authors.initials: RL
authors.lastname: Sack
authors.forename: Brant P
authors.initials: BP
authors.lastname: Hasler
authors.forename: Rebecca A
authors.initials: RA
authors.lastname: Bernert
mesh_terms: D000328:Adult; D001766:Blindness / Q000503:physiopathology*; D002940:Circadian Rhythm / Q000187:drug effects* / Q000502:physiology; D005260:Female; D006801:Humans; D008297:Male; D008550:Melatonin / Q000008:administration & dosage* / Q000502:physiology; D008875:Middle Aged; D008954:Models, Biological
chemical_list: D008550:Melatonin