title: Physical activity, leisure-time screen use and depression among children and young adolescents.
abstract: OBJECTIVE
  Adolescent mental disorders remain a relatively neglected area of research, despite evidence that these conditions affect youth disproportionately. We examined associations between physical activity, leisure-time screen use and depressive symptoms among Australian children and adolescents.
  
  
  METHODS
  Large cross-sectional observational study.
  
  
  METHODS
  Self-reported physical activity and leisure-time screen behaviours, and depressive symptoms using the Short Mood and Feeling Questionnaire were assessed in 8256 students aged 10-16 years (mean age=11.5 years, SD=0.8).
  
  
  RESULTS
  Thirty three percent of the sample reported moderate to high depressive symptoms, with rates higher among females (OR=1.18; 95% CI: 1.02, 1.36; p=0.001). Increased opportunities to be active at school outside class (OR=0.70; 0.58, 0.85; p<0.001), being active in physical education classes (OR=0.77; 0.69, 0.86; p<0.001), greater involvement in sports teams at school (OR=0.77; 0.67, 0.88; p<0.001) and outside of school (OR=0.84; 0.73, 0.96; p=0.01) were all independently associated with lower odds for depressive symptoms. Meeting recommended guidelines for physical activity (OR=0.62; 0.44, 0.88; p=0.007) and, for 12-14 year olds, leisure-time screen use (OR=0.77; 0.59, 0.99; p=0.04) were also independently associated with lower odds for depressive symptoms.
  
  
  CONCLUSIONS
  Higher levels of physical activity among children and young adolescents, and lower levels of leisure-time screen use among young adolescents, are associated with lower depressive symptoms. Longitudinal studies are needed to understand the causal relationships between these variables.
authors: School of Exercise and Nutrition Sciences, Deakin University, Australia. Electronic address: peter.kremer@deakin.edu.au.
authors: Peter
authors: P
authors: Kremer
authors: School of Psychology, Deakin University, Australia.
authors: Christine
authors: C
authors: Elshaug
authors: Department of Nutrition and Dietetics, School of Medicine, Flinders University, Australia.
authors: Eva
authors: E
authors: Leslie
authors: School of Psychology and Centre for Mental Health and Wellbeing Research, Deakin University, Australia.
authors: John W
authors: JW
authors: Toumbourou
authors: Centre for Adolescent Health, Royal Children's Hospital, Australia; Murdoch Children's Research Institute, Australia; Department of Paediatrics, The University of Melbourne, Australia.
authors: George C
authors: GC
authors: Patton
authors: School of Psychology, Deakin University, Australia; Centre for Adolescent Health, Royal Children's Hospital, Australia; Murdoch Children's Research Institute, Australia; Department of Paediatrics, The University of Melbourne, Australia.
authors: Joanne
authors: J
authors: Williams
mesh_terms: D000293:Adolescent; D000294:Adolescent Behavior / Q000523:psychology; D001315:Australia / Q000453:epidemiology; D002648:Child; D003201:Computers / Q000706:statistics & numerical data*; D003430:Cross-Sectional Studies; D003863:Depression / Q000453:epidemiology*; D005260:Female; D006306:Health Surveys; D006801:Humans; D008297:Male; D009043:Motor Activity; D012737:Sex Factors; D013177:Sports / Q000523:psychology; D011795:Surveys and Questionnaires; D013690:Television / Q000706:statistics & numerical data*; D013997:Time Factors; D018910:Video Games / Q000706:statistics & numerical data*
keywords: Adolescents; Children; Depression; Exercise; Physical fitness; Television