title: In pre-school children, sleep objectively assessed via actigraphy remains stable over 12 months and is related to psychological functioning, but not to cortisol secretion.
abstract: OBJECTIVE
  Studies of the long-term stability of sleep in pre-schoolers are scarce. The aim of the present study was to investigate objectively assessed sleep via actigraphy in pre-schoolers longitudinally, and to predict sleep, psychological functioning and cortisol secretion prospectively as a function of sleep 12 months earlier.
  
  
  METHODS
  A total of 73 pre-schoolers (mean age: 5.45 years; 53% females) were assessed again after 12 (mean age: 6.4 years). Sleep-actigraphy recordings were performed, saliva cortisol was analysed, and parents and experts rated children's psychological functioning.
  
  
  RESULTS
  Longitudinally, poor sleep at age 5.45 years was associated with poor sleep and internalizing and peer problems but not with externalizing problems and hyperactivity, and cortisol secretion 12 months later. At age 6.4 years and cross-sectionally, poor sleep was concurrently associated with greater psychological difficulties and increased cortisol secretion.
  
  
  CONCLUSIONS
  In pre-schoolers, poor sleep objectively assessed at age five was associated with psychological difficulties and poor sleep as assessed via actigraph and one year later. Results indicate that in pre-schoolers sleep remains stable over a 12-mont interval. Pre-schoolers with poor sleep appear to be at risk for developing further psychological difficulties.
authors.affiliation: Psychiatric Services Solothurn, Department of Adult Psychiatry, Solothurn, Switzerland; Center for Affective, Stress and Sleep Disorders (ZASS), Psychiatric Clinics of the University of Basel, Switzerland.
authors.forename: Martin
authors.initials: M
authors.lastname: Hatzinger
authors.affiliation: Center for Affective, Stress and Sleep Disorders (ZASS), Psychiatric Clinics of the University of Basel, Switzerland; Department of Sport, Exercise and Health, Division of Sport Science, University of Basel, Basel, Switzerland. Electronic address: serge.brand@upkbs.ch.
authors.forename: Serge
authors.initials: S
authors.lastname: Brand
authors.affiliation: University of Konstanz and Thurgau, University of Teacher Education, Switzerland.
authors.forename: Sonja
authors.initials: S
authors.lastname: Perren
authors.affiliation: Institute of Psychology, University of Zurich, Switzerland.
authors.forename: Agnes
authors.initials: A
authors.lastname: Von Wyl
authors.affiliation: Department of Child and Adolescent Psychiatry, Psychotherapy, and Psychosomatics, University of Leipzig, Germany.
authors.forename: Stephanie
authors.initials: S
authors.lastname: Stadelmann
authors.affiliation: Department of Child and Adolescent Psychiatry, Psychotherapy, and Psychosomatics, University of Leipzig, Germany.
authors.forename: Kai
authors.initials: K
authors.lastname: von Klitzing
authors.affiliation: Center for Affective, Stress and Sleep Disorders (ZASS), Psychiatric Clinics of the University of Basel, Switzerland.
authors.forename: Edith
authors.initials: E
authors.lastname: Holsboer-Trachsler
mesh_terms: D056044:Actigraphy; D002648:Child; D002675:Child, Preschool; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D006854:Hydrocortisone / Q000378:metabolism*; D008137:Longitudinal Studies; D008297:Male; D001523:Mental Disorders / Q000150:complications / Q000503:physiopathology*; D010290:Parents; D012307:Risk Factors; D012463:Saliva / Q000378:metabolism*; D012890:Sleep / Q000502:physiology*; D012893:Sleep Wake Disorders / Q000150:complications / Q000503:physiopathology*
chemical_list: D006854:Hydrocortisone
keywords: Cortisol secretion; Longitudinal study; Pre-schoolers; Psychological functioning; Sleep-actigraphy