title: Idiopathic chronic sleep onset insomnia in attention-deficit/hyperactivity disorder: a circadian rhythm sleep disorder.
abstract: To investigate whether ADHD-related sleep-onset insomnia (SOI) is a circadian rhythm disorder, we compared actigraphic sleep estimates, the circadian rest-activity rhythm, and dim light melatonin onset (DLMO) in ADHD children having chronic idiopathic SOI with that in ADHD children without sleep problems. Participants were 87 psychotropic-medication-naïve children, aged 6 to 12 yrs, with rigorously diagnosed ADHD and SOI (ADHD-SOI) and 33 children with ADHD without SOI (ADHD-noSOI) referred from community mental health institutions and pediatric departments of non-academic hospitals in The Netherlands. Measurements were 1 wk, 24 h actigraphy recordings and salivary DLMO. The mean (+/-SD) sleep onset time was 21:38 +/- 0:54 h in ADHD-SOI, which was significantly (p < 0.001) later than that of 20:49 +/- 0:49 h in ADHD-noSOI. DLMO was significantly later in ADHD-SOI (20:32 +/- 0:55 h), compared with ADHD-noSOI (19:47 +/- 0:49 h; p < 0.001). Wake-up time in ADHD-SOI was later than in ADHD-noSOI (p = 0.002). There were no significant between-group differences in sleep maintenance, as estimated by number of wake bouts and activity level in the least active 5 h period, or inter- and intradaily rhythm variability. We conclude that children with ADHD and chronic idiopathic sleep-onset insomnia show a delayed sleep phase and delayed DLMO, compared with ADHD children without SOI.
authors.affiliation: Department of Child and Adolescent Psychiatry, University of Amsterdam, Amsterdam, The Netherlands.
authors.forename: Kristiaan B
authors.initials: KB
authors.lastname: Van der Heijden
authors.forename: Marcel G
authors.initials: MG
authors.lastname: Smits
authors.forename: Eus J W
authors.initials: EJ
authors.lastname: Van Someren
authors.forename: W Boudewijn
authors.initials: WB
authors.lastname: Gunning
mesh_terms: D001289:Attention Deficit Disorder with Hyperactivity / Q000503:physiopathology*; D002648:Child; D003627:Data Interpretation, Statistical; D004784:Environmental Monitoring; D006801:Humans; D008027:Light; D008550:Melatonin / Q000378:metabolism; D020178:Sleep Disorders, Circadian Rhythm / Q000503:physiopathology*; D007319:Sleep Initiation and Maintenance Disorders / Q000503:physiopathology*
chemical_list: D008550:Melatonin