Lewy Alfred J, Emens Jonathan, Sack Robert L, Hasler Brant P, Bernert Rebecca A
Sleep and Mood Disorders Laboratory, Department of Psychiatry, Oregon Health & Science University, Portland, Oregon, USA.
Chronobiol Int. 2003 Sep;20(5):837-52. doi: 10.1081/cbi-120024215.
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.
