title: Prevalence of insomnia symptoms in a general population sample of young children and preadolescents: gender effects.
abstract: OBJECTIVE
  Our population-based study examined the prevalence of insomnia symptoms and its sociodemographic, subjective, and polysomnographic (PSG) sleep risk factors in young and preadolescent children.
  
  
  METHODS
  We performed a cross-sectional study of 700 children, ages 5-12 years who underwent a 9-h PSG and parent-completed sleep and development questionnaires (Penn State Child Cohort). Insomnia symptoms were defined as parent report of difficulty falling or staying asleep and sleep-disordered breathing (SDB) as an apnea hypopnea index of ≥1.
  
  
  RESULTS
  The prevalence of insomnia symptoms was 19.3% and did not significantly change (20.2%) when children with SDB were excluded. A significant interaction between gender and age revealed that the prevalence of insomnia symptoms was highest in girls ages 11 to 12 years (30.6%). This gender difference was not associated with significant differences between girls and boys ages 11-12 years in anxiety and depressive symptoms. In contrast girls ages 11-12 years with insomnia symptoms, but not boys of the same group, demonstrated clinically significant PSG sleep disturbances compared to those without insomnia symptoms.
  
  
  CONCLUSIONS
  These data suggest that one out of five young children and preadolescents of the general population have insomnia symptoms. Importantly, the prevalence of insomnia symptoms peaks in girls ages 11 to 12 years and is associated with objective sleep disturbances which may be related to hormonal changes associated with the onset of puberty rather than anxiety and depression.
authors: Sleep Research and Treatment Center, Department of Psychiatry, Pennsylvania State University College of Medicine, Hershey, PA, United States. Electronic address: scalhoun@psu.edu.
authors: Susan L
authors: SL
authors: Calhoun
authors: Sleep Research and Treatment Center, Department of Psychiatry, Pennsylvania State University College of Medicine, Hershey, PA, United States.
authors: Julio
authors: J
authors: Fernandez-Mendoza
authors: Sleep Research and Treatment Center, Department of Psychiatry, Pennsylvania State University College of Medicine, Hershey, PA, United States.
authors: Alexandros N
authors: AN
authors: Vgontzas
authors: Department of Public Health Sciences, Pennsylvania State University College of Medicine, Hershey, PA, United States.
authors: Duanping
authors: D
authors: Liao
authors: Sleep Research and Treatment Center, Department of Psychiatry, Pennsylvania State University College of Medicine, Hershey, PA, United States.
authors: Edward O
authors: EO
authors: Bixler
mesh_terms: D001007:Anxiety / Q000453:epidemiology; D002648:Child; D003863:Depression / Q000453:epidemiology; D005260:Female; D006728:Hormones / Q000502:physiology; D006801:Humans; D016015:Logistic Models; D008297:Male; D010290:Parents; D015995:Prevalence; D011627:Puberty / Q000502:physiology; D012727:Sex Characteristics; D017678:Sex Distribution; D012890:Sleep; D012891:Sleep Apnea Syndromes / Q000453:epidemiology* / Q000503:physiopathology; D007319:Sleep Initiation and Maintenance Disorders / Q000453:epidemiology* / Q000503:physiopathology
chemical_list: D006728:Hormones
keywords: Epidemiology; Gender; Insomnia; Preadolescent children; Puberty; Sociodemographics