title: Job strain as a risk factor for clinical depression: systematic review and meta-analysis with additional individual participant data.
abstract: BACKGROUND
  Adverse psychosocial working environments characterized by job strain (the combination of high demands and low control at work) are associated with an increased risk of depressive symptoms among employees, but evidence on clinically diagnosed depression is scarce. We examined job strain as a risk factor for clinical depression.
  
  
  METHODS
  We identified published cohort studies from a systematic literature search in PubMed and PsycNET and obtained 14 cohort studies with unpublished individual-level data from the Individual-Participant-Data Meta-analysis in Working Populations (IPD-Work) Consortium. Summary estimates of the association were obtained using random-effects models. Individual-level data analyses were based on a pre-published study protocol.
  
  
  RESULTS
  We included six published studies with a total of 27 461 individuals and 914 incident cases of clinical depression. From unpublished datasets we included 120 221 individuals and 982 first episodes of hospital-treated clinical depression. Job strain was associated with an increased risk of clinical depression in both published [relative risk (RR) = 1.77, 95% confidence interval (CI) 1.47-2.13] and unpublished datasets (RR = 1.27, 95% CI 1.04-1.55). Further individual participant analyses showed a similar association across sociodemographic subgroups and after excluding individuals with baseline somatic disease. The association was unchanged when excluding individuals with baseline depressive symptoms (RR = 1.25, 95% CI 0.94-1.65), but attenuated on adjustment for a continuous depressive symptoms score (RR = 1.03, 95% CI 0.81-1.32).
  
  
  CONCLUSIONS
  Job strain may precipitate clinical depression among employees. Future intervention studies should test whether job strain is a modifiable risk factor for depression.
authors.affiliation: National Research Centre for the Working Environment,DK-2100 Copenhagen Ø,Denmark.
authors.forename: I E H
authors.initials: IEH
authors.lastname: Madsen
authors.affiliation: Finnish Institute of Occupational Health,FI-00250 Helsinki,Finland.
authors.forename: S T
authors.initials: ST
authors.lastname: Nyberg
authors.affiliation: Stress Research Institute, Stockholm University,SE-106 91 Stockholm,Sweden.
authors.forename: L L
authors.initials: LL
authors.lastname: Magnusson Hanson
authors.affiliation: Department of Epidemiology and Public Health,University College London,London WC1E 6BT,UK.
authors.forename: J E
authors.initials: JE
authors.lastname: Ferrie
authors.affiliation: Finnish Institute of Occupational Health,FI-00250 Helsinki,Finland.
authors.forename: K
authors.initials: K
authors.lastname: Ahola
authors.affiliation: Institute of Environmental Medicine,Karolinska Institutet,SE-171 77 Stockholm,Sweden.
authors.forename: L
authors.initials: L
authors.lastname: Alfredsson
authors.affiliation: Department of Epidemiology and Public Health,University College London,London WC1E 6BT,UK.
authors.forename: G D
authors.initials: GD
authors.lastname: Batty
authors.affiliation: National Research Centre for the Working Environment,DK-2100 Copenhagen Ø,Denmark.
authors.forename: J B
authors.initials: JB
authors.lastname: Bjorner
authors.affiliation: Department of Occupational and Environmental Medicine,Bispebjerg University Hospital,DK-2400 Copenhagen,Denmark.
authors.forename: M
authors.initials: M
authors.lastname: Borritz
authors.affiliation: Federal Institute for Occupational Safety and Health (BAuA),D-10317 Berlin,Germany.
authors.forename: H
authors.initials: H
authors.lastname: Burr
authors.affiliation: INSERM, U1085, Research Institute for Environmental and Occupational Health (IRSET), Epidemiology in Occupational Health and Ergonomics (ESTER) Team, F-49000, Angers,France.
authors.forename: J-F
authors.initials: JF
authors.lastname: Chastang
authors.affiliation: Netherlands Institute of Mental Health and Addiction,3521 VS Utrecht,The Netherlands.
authors.forename: R
authors.initials: R
authors.lastname: de Graaf
authors.affiliation: Department of Medical Sociology,University of Düsseldorf,40225 Düsseldorf,Germany.
authors.forename: N
authors.initials: N
authors.lastname: Dragano
authors.affiliation: Department of Epidemiology and Public Health,University College London,London WC1E 6BT,UK.
authors.forename: M
authors.initials: M
authors.lastname: Hamer
authors.affiliation: Institute of Behavioral Sciences,University of Helsinki,FI-00014 Helsinki,Finland.
authors.forename: M
authors.initials: M
authors.lastname: Jokela
authors.affiliation: Department of Health Sciences,Mid Sweden University,SE-851 70 Sundsvall,Sweden.
authors.forename: A
authors.initials: A
authors.lastname: Knutsson
authors.affiliation: Department of Public Health,University of Helsinki,FI-00014 Helsinki,Finland.
authors.forename: M
authors.initials: M
authors.lastname: Koskenvuo
authors.affiliation: Finnish Institute of Occupational Health,FI-00250 Helsinki,Finland.
authors.forename: A
authors.initials: A
authors.lastname: Koskinen
authors.affiliation: Stress Research Institute, Stockholm University,SE-106 91 Stockholm,Sweden.
authors.forename: C
authors.initials: C
authors.lastname: Leineweber
authors.affiliation: INSERM, U1085, Research Institute for Environmental and Occupational Health (IRSET), Epidemiology in Occupational Health and Ergonomics (ESTER) Team, F-49000, Angers,France.
authors.forename: I
authors.initials: I
authors.lastname: Niedhammer
authors.affiliation: Unit of Social Medicine,Frederiksberg University Hospital,DK-2000 Copenhagen,Denmark.
authors.forename: M L
authors.initials: ML
authors.lastname: Nielsen
authors.affiliation: Stress Research Institute, Stockholm University,SE-106 91 Stockholm,Sweden.
authors.forename: M
authors.initials: M
authors.lastname: Nordin
authors.affiliation: Finnish Institute of Occupational Health,FI-00250 Helsinki,Finland.
authors.forename: T
authors.initials: T
authors.lastname: Oksanen
authors.affiliation: The Danish National Centre for Social Research,DK-1052 Copenhagen,Denmark.
authors.forename: J H
authors.initials: JH
authors.lastname: Pejtersen
authors.affiliation: Finnish Institute of Occupational Health,FI-00250 Helsinki,Finland.
authors.forename: J
authors.initials: J
authors.lastname: Pentti
authors.affiliation: The Netherlands Institute for Social Research,2515 XP The Hague,The Netherlands.
authors.forename: I
authors.initials: I
authors.lastname: Plaisier
authors.affiliation: Finnish Institute of Occupational Health,FI-00250 Helsinki,Finland.
authors.forename: P
authors.initials: P
authors.lastname: Salo
authors.affiliation: Department of Epidemiology and Public Health,University College London,London WC1E 6BT,UK.
authors.forename: A
authors.initials: A
authors.lastname: Singh-Manoux
authors.affiliation: Folkhälsan Research Center,FI-00290 Helsinki,Finland.
authors.forename: S
authors.initials: S
authors.lastname: Suominen
authors.affiliation: Netherlands Institute of Mental Health and Addiction,3521 VS Utrecht,The Netherlands.
authors.forename: M
authors.initials: M
authors.lastname: Ten Have
authors.affiliation: Stress Research Institute, Stockholm University,SE-106 91 Stockholm,Sweden.
authors.forename: T
authors.initials: T
authors.lastname: Theorell
authors.affiliation: Finnish Institute of Occupational Health,FI-00250 Helsinki,Finland.
authors.forename: S
authors.initials: S
authors.lastname: Toppinen-Tanner
authors.affiliation: Finnish Institute of Occupational Health,FI-00250 Helsinki,Finland.
authors.forename: J
authors.initials: J
authors.lastname: Vahtera
authors.affiliation: Finnish Institute of Occupational Health,FI-00250 Helsinki,Finland.
authors.forename: A
authors.initials: A
authors.lastname: Väänänen
authors.affiliation: Occupational and Environmental Medicine,Uppsala University,SE-751 85 Uppsala,Sweden.
authors.forename: P J M
authors.initials: PJM
authors.lastname: Westerholm
authors.affiliation: Stress Research Institute, Stockholm University,SE-106 91 Stockholm,Sweden.
authors.forename: H
authors.initials: H
authors.lastname: Westerlund
authors.affiliation: Stress Research Institute, Stockholm University,SE-106 91 Stockholm,Sweden.
authors.forename: E I
authors.initials: EI
authors.lastname: Fransson
authors.affiliation: Finnish Institute of Occupational Health,FI-00250 Helsinki,Finland.
authors.forename: K
authors.initials: K
authors.lastname: Heikkilä
authors.affiliation: Finnish Institute of Occupational Health,FI-00250 Helsinki,Finland.
authors.forename: M
authors.initials: M
authors.lastname: Virtanen
authors.affiliation: National Research Centre for the Working Environment,DK-2100 Copenhagen Ø,Denmark.
authors.forename: R
authors.initials: R
authors.lastname: Rugulies
authors.affiliation: Finnish Institute of Occupational Health,FI-00250 Helsinki,Finland.
authors.forename: M
authors.initials: M
authors.lastname: Kivimäki
mesh_terms: D003866:Depressive Disorder / Q000209:etiology*; D006801:Humans; D000073397:Occupational Stress / Q000150:complications*
keywords: Observational studies; occupational health; work stress