title: Sleep and behavioural problems associate with low mood in Finnish children aged 4-12 years: an epidemiological study.
abstract: BACKGROUND
  Few studies have examined the associations between sleep, mood and behaviour in young children in the early stages of developing psychopathology. The purpose here was to examine the association of emotional problems, especially mood, with family and child characteristics, sleep and behavioural problems in 4-12 year-old children.
  
  
  METHODS
  The sample was population-based and included 1714 children. Parents filled in the Strengths and Difficulties Questionnaire and a background questionnaire on child and family characteristics. The associations between (a) emotional symptoms/mood and background variables, (b) emotional problems and conduct problems/hyperactivity and (c) mood and conduct problems/hyperactivity were examined with ordinal regression in univariate and multivariate models.
  
  
  RESULTS
  Of the background variables, child's sleeping problems had the most powerful association with emotional symptoms and mood. Abnormal emotional problems score and emotional symptoms were associated with abnormal conduct problems and hyperactivity scores. Of the emotional symptoms, low mood was the one associated most strongly with conduct problems and hyperactivity after controlling for all significant background variables and other emotional symptoms.
  
  
  CONCLUSIONS
  We conclude that in young children sleep problems associate with low mood. Low mood associates with behavioural problems. When a child presents with low mood or behavioural problems, a comprehensive assessment of their psychiatric symptoms, as well as their sleep problems, is recommended.
authors.affiliation: Laboratory of Developmental Psychopathology, Helsinki Pediatric Research Center, Children's Hospital, Child Psychiatry, University of Helsinki and Helsinki University Hospital, Tukholmankatu 8 C 613, 00290 Helsinki, Finland.
authors.forename: K
authors.identifier: 0000-0002-2052-7147
authors.initials: K
authors.lastname: Maasalo
authors.affiliation: Children's Hospital, Child Psychiatry, Helsinki University Hospital, PL 355, 00029 HUS Helsinki, Finland.
authors.forename: T
authors.initials: T
authors.lastname: Fontell
authors.affiliation: Laboratory of Developmental Psychopathology, Helsinki Pediatric Research Center, Children's Hospital, Child Psychiatry, University of Helsinki and Helsinki University Hospital, PL 353, 00029 HUS Helsinki, Finland.
authors.forename: J
authors.initials: J
authors.lastname: Wessman
authors.affiliation: Laboratory of Developmental Psychopathology, Helsinki Pediatric Research Center, Children's Hospital, Child Psychiatry, University of Helsinki and Helsinki University Hospital, Lastenlinnantie 2, 00250 Helsinki, Finland.
authors.forename: E T
authors.initials: ET
authors.lastname: Aronen
keywords: Behaviour problems; Child development; Mood; Risk factors; Sleep