title: Sedentary behaviour and the risk of depression: a meta-analysis.
abstract: BACKGROUND
  Sedentary behaviour is associated with risk of depression. We review and quantitatively summarise the evidence from observational studies in a meta-analysis.
  
  
  METHODS
  We searched the PubMed, Web of Knowledge, Chinese National Knowledge Infrastructure and Wanfang databases for observational studies related to the association of sedentary behaviour and depression risk up to 15 January 2014. Summary relative risks (RRs) were estimated by the use of a random effects model.
  
  
  RESULTS
  Thirteen cross-sectional studies with 110,152 participants and 11 longitudinal studies with 83,014 participants were included in this meta-analysis. The summary RR of depression for the highest versus non-occasional/occasional sedentary behaviour was 1.25 (95% CI 1.16 to 1.35, I(2)=50.7%) for all included studies. The pooled RRs of depression for sedentary behaviour were 1.31 (95% CI 1.16 to 1.48) in cross-sectional studies and 1.14 (95% CI 1.06 to 1.21) in longitudinal studies. In subgroup analysis by different types of sedentary behaviour, the pooled RRs of depression were 1.13 (95% CI 1.06 to 1.21) for long-time TV viewing and 1.22 (95% CI 1.10 to 1.34) for prolonged computer or internet use.
  
  
  CONCLUSIONS
  This meta-analysis of observational studies indicates that sedentary behaviour is associated with increased risk of depression.
authors.affiliation: Department of Epidemiology and Health Statistics, Qingdao University Medical College, Qingdao, Shandong, China.
authors.forename: Long
authors.initials: L
authors.lastname: Zhai
authors.affiliation: Department of Epidemiology and Health Statistics, Qingdao University Medical College, Qingdao, Shandong, China.
authors.forename: Yi
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: Department of Epidemiology and Health Statistics, Qingdao University Medical College, Qingdao, Shandong, China.
authors.forename: Dongfeng
authors.initials: D
authors.lastname: Zhang
mesh_terms: D003866:Depressive Disorder / Q000209:etiology*; D004812:Epidemiologic Methods; D005260:Female; D006801:Humans; D008297:Male; D017594:Publication Bias; D057185:Sedentary Behavior
keywords: Epidemiology; Psychology