title: Symptoms of Depression and Difficulty Initiating Sleep from Early Adolescence to Early Adulthood: A Longitudinal Study.
abstract: OBJECTIVE
  To assess the direction of the relationship and degree of shared associations between symptoms of depression and difficulty initiating sleep (DIS) from early adolescence to early adulthood.
  
  
  METHODS
  Cross-sectional and longitudinal assessment of the symptoms of depression-DIS association from early adolescence (age 13 y) to early adulthood (age 23 y).
  
  
  METHODS
  Hordaland, Norway.
  
  
  METHODS
  There were 1,105 individuals (55% male) who took part in the Norwegian Longitudinal Health Behaviour Study (NLHB) and participated at least once across seven data collection waves during the years 1990-2000.
  
  
  METHODS
  N/A.
  
  
  RESULTS
  Characteristic data were obtained during the first assessment. Symptoms of depression and instances of DIS were assessed during each data collection wave. Symptoms of depression and DIS were associated in all data waves, and one-step cross-lagged bivariate correlations were significant and comparatively high for both factors. Structural equation modelling indicated that DIS and symptoms of depression at wave 1 remain relatively stable across waves (all P < 0.001), and a significant and consistent unidirectional cross-lagged effect was noted running from symptoms of depression to DIS from early adolescence to early adulthood. DIS is only marginally and inconsistently associated with the lagged symptoms of depression score across waves.
  
  
  CONCLUSIONS
  These results suggest that symptoms of depression established in early adolescence are a moderate predictor of difficulty initiating sleep (DIS) in early adulthood, whereas the reverse association of DIS predicting depression was not convincingly supported. These findings are in contrast to previous findings that suggest sleep problems as a risk factor for the later development of depression.
authors.affiliation: IMPACT SRC, School of Medicine, Deakin University, Geelong, Australia.|Centre for Human Psychopharmacology, Swinburne University of Technology, Hawthorn, Australia.
authors.forename: Amie C
authors.initials: AC
authors.lastname: Hayley
authors.affiliation: Department of Public Mental Health, Division of Mental Health, Norwegian Institute of Public Health, Bergen, Norway.|Alcohol and Drug Research Western Norway, Stavanger University Hospital, Stavanger, Norway.
authors.forename: Jens Christoffer
authors.initials: JC
authors.lastname: Skogen
authors.affiliation: Department of Public Mental Health, Division of Mental Health, Norwegian Institute of Public Health, Bergen, Norway.|Regional Centre for Child and Youth Mental Health and Child Welfare, Uni Research Health, Bergen, Norway.|Department of Psychiatry, Helse Fonna HF, Haugesund, Norway.
authors.forename: Børge
authors.initials: B
authors.lastname: Sivertsen
authors.affiliation: Department of Health Promotion and Development, Faculty of Psychology, University of Bergen, Bergen, Norway.
authors.forename: Bente
authors.initials: B
authors.lastname: Wold
authors.affiliation: IMPACT SRC, School of Medicine, Deakin University, Geelong, Australia.|Department of Psychiatry, The University of Melbourne, Parkville, Australia.|Orygen The National Centre of Excellence in Youth Mental Health, Australia.|Florey Institute for Neuroscience and Mental Health Parkville Australia.
authors.forename: Michael
authors.initials: M
authors.lastname: Berk
authors.affiliation: IMPACT SRC, School of Medicine, Deakin University, Geelong, Australia.|NorthWest Academic Centre, Department of Medicine, The University of Melbourne, St Albans, Australia.
authors.forename: Julie A
authors.initials: JA
authors.lastname: Pasco
authors.affiliation: Department of Public Mental Health, Division of Mental Health, Norwegian Institute of Public Health, Bergen, Norway.|Department of Psychosocial Science, Faculty of Psychology, University of Bergen, Bergen, Norway.
authors.forename: Simon
authors.initials: S
authors.lastname: Øverland
mesh_terms: D000293:Adolescent; D003430:Cross-Sectional Studies; D003863:Depression / Q000150:complications / Q000523:psychology*; D005260:Female; D015438:Health Behavior; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D009664:Norway; D012307:Risk Factors; D007319:Sleep Initiation and Maintenance Disorders / Q000150:complications / Q000503:physiopathology* / Q000523:psychology*; D055815:Young Adult
keywords: adolescence; adulthood; cross-sectional; depression; etiology; longitudinal; risk factor; sleep