Dim light melatonin onset (DLMO): A tool for the analysis of circadian phase in human sleep and chronobiological disorders

• Published in: Progress in neuro-psychopharmacology & biological psychiatry Vol. 31; no. 1; pp. 1 - 11
• Main Authors: Pandi-Perumal, Seithikurippu R., Smits, Marcel, Spence, Warren, Srinivasan, Venkataramanujan, Cardinali, Daniel P., Lowe, Alan D., Kayumov, Leonid
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier Inc 30.01.2007; Elsevier
• Subjects: Adult and adolescent clinical studies; Animals; Biological and medical sciences; Circadian Rhythm - physiology; Circadian rhythms; Delayed sleep phase syndrome; Depression; Dim light melatonin onset; Disorders of higher nervous function. Focal brain diseases. Central vestibular syndrome and deafness. Brain stem syndromes; Humans; Jet Lag Syndrome - physiopathology; Light; Light/dark cycle; Medical sciences; Melatonin; Melatonin - biosynthesis; Mood disorders; Nervous system (semeiology, syndromes); Neurology; Neuropharmacology; Periodicity; Pharmacology. Drug treatments; Psychology. Psychoanalysis. Psychiatry; Psychopathology. Psychiatry; Seasonal affective disorder; Sleep - physiology; Suprachiasmatic Nucleus - physiology; Circadian rhythms; Seasonal affective disorder; Light/dark cycle; Melatonin; Delayed sleep phase syndrome; Mood disorders; Dim light melatonin onset; Human; Mood disorder; Nervous system diseases; Sleep disorder; Depression; Biological rhythm; Circadian rhythm; Sleep; Seasonal variation; Light; Illumination; Neurological disorder; Pineal hormone; Tool
• ISSN: 0278-5846; 1878-4216
• DOI: 10.1016/j.pnpbp.2006.06.020

The circadian rhythm of melatonin in saliva or plasma, or of the melatonin metabolite 6-sulphatoxymelatonin (aMT6S) in urine, is a defining feature of suprachiasmatic nucleus (SCN) function, the endogenous oscillatory pacemaker. A substantial number of studies have shown that, within this rhythmic profile, the onset of melatonin secretion under dim light conditions (the dim light melatonin onset or DLMO) is the single most accurate marker for assessing the circadian pacemaker. Additionally, melatonin onset has been used clinically to evaluate problems related to the onset or offset of sleep. DLMO is useful for determining whether an individual is entrained (synchronized) to a 24-h light/dark (LD) cycle or is in a free-running state. DLMO is also useful for assessing phase delays or advances of rhythms in entrained individuals. Additionally, it has become an important tool for psychiatric diagnosis, its use being recommended for phase typing in patients suffering from sleep and mood disorders. More recently, DLMO has also been used to assess the chronobiological features of seasonal affective disorder (SAD). DLMO marker is also useful for identifying optimal application times for therapies such as bright light or exogenous melatonin treatment.