title: Familial Aggregation of Insomnia.
abstract: There is little information about familial aggregation of insomnia; however, this type of information is important to (1) improve our understanding of insomnia risk factors and (2) to design more effective treatment and prevention programs. This study aimed to investigate evidence of familial aggregation of insomnia among first-degree relatives of probands with and without insomnia.
  
  
  
  Cases (n = 134) and controls (n = 145) enrolled in a larger epidemiological study were solicited to invite their first-degree relatives and spouses to complete a standardized sleep/insomnia survey. In total, 371 first-degree relatives (Mage = 51.9 years, SD = 18.0; 34.3% male) and 138 spouses (Mage = 55.5 years, SD = 12.2; 68.1% male) completed the survey assessing the nature, severity, and frequency of sleep disturbances. The dependent variable was insomnia in first-degree relatives and spouses. Familial aggregation was claimed if the risk of insomnia was significantly higher in the exposed (relatives of cases) compared to the unexposed cohort (relatives of controls). The risk of insomnia was also compared between spouses in the exposed (spouses of cases) and unexposed cohort (spouses of controls).
  
  
  
  The risk of insomnia in exposed and unexposed biological relatives was 18.6% and 10.4%, respectively, yielding a relative risk (RR) of 1.80 (p = .04) after controlling for age and sex. The risk of insomnia in exposed and unexposed spouses was 9.1% and 4.2%, respectively; however, corresponding RR of 2.13 (p = .28) did not differ significantly.
  
  
  
  Results demonstrate evidence of strong familial aggregation of insomnia. Additional research is warranted to further clarify and disentangle the relative contribution of genetic and environmental factors in insomnia.
authors.affiliation: École de psychologie, Université Laval, Québec City, Québec, Canada.|Centre d'étude des troubles du sommeil, Centre de recherche de l'Institut universitaire en santé mentale de Québec, Québec City, Québec, Canada.
authors.forename: Denise C
authors.initials: DC
authors.lastname: Jarrin
authors.affiliation: École de psychologie, Université Laval, Québec City, Québec, Canada.|Centre d'étude des troubles du sommeil, Centre de recherche de l'Institut universitaire en santé mentale de Québec, Québec City, Québec, Canada.
authors.forename: Charles M
authors.initials: CM
authors.lastname: Morin
authors.affiliation: École de psychologie, Université Laval, Québec City, Québec, Canada.|Centre d'étude des troubles du sommeil, Centre de recherche de l'Institut universitaire en santé mentale de Québec, Québec City, Québec, Canada.
authors.forename: Amélie
authors.initials: A
authors.lastname: Rochefort
authors.affiliation: École de psychologie, Université Laval, Québec City, Québec, Canada.|Centre d'étude des troubles du sommeil, Centre de recherche de l'Institut universitaire en santé mentale de Québec, Québec City, Québec, Canada.
authors.forename: Hans
authors.initials: H
authors.lastname: Ivers
authors.affiliation: National Reference Centre for Orphan Diseases, Narcolepsy, Sleep Unit, Department of Neurology, Gui de Chauliac Hospital, CHU Montpellier, Inserm, U1061 Montpellier, France.
authors.forename: Yves A
authors.initials: YA
authors.lastname: Dauvilliers
authors.affiliation: École de psychologie, Université Laval, Québec City, Québec, Canada.
authors.forename: Josée
authors.initials: J
authors.lastname: Savard
authors.affiliation: École de psychologie, Université Laval, Québec City, Québec, Canada.
authors.forename: Mélanie
authors.initials: M
authors.lastname: LeBlanc
authors.affiliation: Centre d'étude des troubles du sommeil, Centre de recherche de l'Institut universitaire en santé mentale de Québec, Québec City, Québec, Canada.
authors.forename: Chantal
authors.initials: C
authors.lastname: Merette
mesh_terms: D000328:Adult; D016022:Case-Control Studies; D015331:Cohort Studies; D005190:Family; D005260:Female; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D012307:Risk Factors; D007319:Sleep Initiation and Maintenance Disorders / Q000175:diagnosis / Q000453:epidemiology* / Q000235:genetics*; D012893:Sleep Wake Disorders / Q000175:diagnosis / Q000453:epidemiology / Q000235:genetics; D018454:Spouses; D011795:Surveys and Questionnaires
keywords: epidemiology; family aggregation; insomnia; predisposition.; risk factors