title: Dim light melatonin onset (DLMO): a tool for the analysis of circadian phase in human sleep and chronobiological disorders.
abstract: 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.
authors.affiliation: Comprehensive Center for Sleep Medicine, Department of Pulmonary, Critical Care, and Sleep Medicine, Mount Sinai School of Medicine, New York, NY 10029, USA. pandiperumal@gmail.com
authors.forename: Seithikurippu R
authors.initials: SR
authors.lastname: Pandi-Perumal
authors.forename: Marcel
authors.initials: M
authors.lastname: Smits
authors.forename: Warren
authors.initials: W
authors.lastname: Spence
authors.forename: Venkataramanujan
authors.initials: V
authors.lastname: Srinivasan
authors.forename: Daniel P
authors.initials: DP
authors.lastname: Cardinali
authors.forename: Alan D
authors.initials: AD
authors.lastname: Lowe
authors.forename: Leonid
authors.initials: L
authors.lastname: Kayumov
mesh_terms: D000818:Animals; D002940:Circadian Rhythm / Q000502:physiology*; D006801:Humans; D020179:Jet Lag Syndrome / Q000503:physiopathology; D008027:Light; D008550:Melatonin / Q000096:biosynthesis*; D010507:Periodicity; D012890:Sleep / Q000502:physiology*; D013493:Suprachiasmatic Nucleus / Q000502:physiology
chemical_list: D008550:Melatonin