title: A twin-study of sleep difficulties in school-aged children.
abstract: This study examines frequency, overlap, and genetic and environmental influences on sleep difficulties, which are understudied in school-aged children. The Sleep Self Report and the Children's Sleep Habits Questionnaire were completed by 300 twin pairs (aged 8 years) and their parents. Child report suggested more frequent sleep problems than parent report (e.g., regular sleep onset delay was reported by 45% of children and 17% of parents). Associations between most of the sleep difficulties were small but significant (e.g., r(s)=.16 for parent report of bedtime resistance and sleep onset delay). Twin correlations based on parent reports suggest greater genetic influence (M=50%) than those based on child self-report (M=18%). Possible rater effects should be considered when evaluating children's sleep problems.
authors.affiliation: Institute of Psychiatry, King's College, De Crespigny Park, London SE58AF. a.gregory@iop.kcl.ac.uk
authors.forename: Alice M
authors.initials: AM
authors.lastname: Gregory
authors.forename: Frühling V
authors.initials: FV
authors.lastname: Rijsdijk
authors.forename: Thalia C
authors.initials: TC
authors.lastname: Eley
mesh_terms: D002648:Child; D005260:Female; D006801:Humans; D008297:Male; D015995:Prevalence; D012893:Sleep Wake Disorders / Q000453:epidemiology*; D013334:Students; D011795:Surveys and Questionnaires; D014427:Twins