title: Self-reported sleep quality, weight status and depression in young adult twins and siblings.
abstract: BACKGROUND
  Research supporting relationships between sleep quality, weight, depression and anxiety has typically examined the relationships separately rather than simultaneously, potentially hampering insights into the characteristics of reported links. This study aimed to fill this gap in the research to provide further insight into the factors associated with sleep.
  
  
  METHODS
  Data from wave 4 of the G1219 cohort were used in cross-sectional analyses. The sample comprised 1392 adult twins and siblings aged 18-27 years. Participants completed a self-report questionnaire which included the Pittsburgh Sleep Quality Index as a measure of sleep quality, the Short Mood and Feelings Questionnaire as a measure of depression symptoms and the Revised Symptoms of Anxiety Scale as a measure of anxiety symptoms. Participants were asked to self-report general health and weight and height so researchers could derive weight status from measures of body mass index.
  
  
  RESULTS
  An analysis of covariance including weight status, depression, anxiety and general health as predictors and sleep quality as the outcome revealed main effects of depression (F(3,1163) = 10.93, p < 0.001) and general health (F(4,1163) = 5.72, p < 0.001) only.
  
  
  CONCLUSIONS
  A direct relationship between weight and sleep should not be assumed as it is possible that the relationship is at least in part accounted for by depression symptoms or general health. Depression symptoms and general health may also account for the association between sleep quality and anxiety symptoms in young adults.
authors.affiliation: Health Behaviour Research Centre, Department of Epidemiology and Public Health, University College London, Gower Street, London, WC1E 6BT UK.
authors.forename: Alexia
authors.initials: A
authors.lastname: Sawyer
authors.affiliation: Health Behaviour Research Centre, Department of Epidemiology and Public Health, University College London, Gower Street, London, WC1E 6BT UK.
authors.forename: Abi
authors.initials: A
authors.lastname: Fisher
authors.affiliation: Health Behaviour Research Centre, Department of Epidemiology and Public Health, University College London, Gower Street, London, WC1E 6BT UK.
authors.forename: Clare
authors.initials: C
authors.lastname: Llewellyn
authors.affiliation: Department of Psychology, Goldsmiths, University of London, New Cross, London, SE14 6NW UK.
authors.forename: Alice M
authors.initials: AM
authors.lastname: Gregory
keywords: Depression; Obesity; Overweight; Sleep; Young adults