Capturing the circadian rhythms of free-running blind people with 0.5 mg melatonin

• Published in: Brain research Vol. 918; no. 1; pp. 96 - 100
• Main Authors: Lewy, Alfred J, Bauer, Vance K, Hasler, Brant P, Kendall, Adam R, Pires, M.Laura N, Sack, Robert L
• Format: Journal Article
• Language: English
• Published: London Elsevier B.V 09.11.2001; Amsterdam Elsevier; New York, NY
• Subjects: Adult; Biological and medical sciences; Biological Clocks - drug effects; Biological Clocks - physiology; Blindness - complications; Blindness - metabolism; Blindness - physiopathology; Circadian rhythm; Circadian Rhythm - drug effects; Circadian Rhythm - physiology; Dose-Response Relationship, Drug; Drug Administration Schedule; Female; Fundamental and applied biological sciences. Psychology; Hormones and neuropeptides. Regulation; Humans; Hypothalamus. Hypophysis. Epiphysis. Urophysis; Intrinsic period (tau); Male; Melatonin; Melatonin - administration & dosage; Melatonin - adverse effects; Melatonin - blood; Melatonin onset (MO); Middle Aged; Pineal Gland - metabolism; Pineal Gland - physiopathology; Sleep Disorders, Circadian Rhythm - drug therapy; Sleep Disorders, Circadian Rhythm - etiology; Sleep Disorders, Circadian Rhythm - physiopathology; Suprachiasmatic Nucleus - drug effects; Suprachiasmatic Nucleus - metabolism; Vertebrates: endocrinology; Visual Pathways - injuries; Visual Pathways - physiopathology; Intrinsic period (tau); Melatonin; Circadian rhythm; Neural basis of behavior; Melatonin onset (MO); Human; Biological rhythm; Blindness; Pineal hormone
• ISSN: 0006-8993; 1872-6240
• DOI: 10.1016/S0006-8993(01)02964-X

We have recently shown that six of seven totally blind people (who had free-running circadian rhythms with periods longer than 24 h) could be entrained (synchronized) to a nightly dose of 10 mg melatonin. After treatment discontinuation and re-entrainment to the 10 mg dose, we further found in three of these subjects that the dose could be gradually reduced to 0.5 mg without loss of effect. The question then arose: can a de novo (starting) dose of 0.5 mg initially capture free-running rhythms? Following withdrawal of the stepped-down 0.5 mg dose and consequent release into a free-run, the same three individuals were given 0.5 mg of melatonin de novo. All entrained within a few weeks.