title: Synergistic interaction effect between job control and social support at work on general psychological distress.
abstract: OBJECTIVE
  Little is known about the interaction between job control and social support at work on common mental disorders. To examine whether there is a synergistic interaction effect between job control and social support at work on general psychological distress and whether it differs by the level of job demands.
  
  
  METHODS
  About 1,940 male and female workers from the Malmö Shoulder and Neck Study were chosen for this cross-sectional study. Job control, social support at work, and job demands were measured by the Swedish version of the Job Content Questionnaire, and general psychological distress was assessed by the General Health Questionnaire.
  
  
  RESULTS
  A significant excessive risk increase for general psychological distress was observed when workers had both low job control and low social support at work in both men and women. The synergistic effect was stronger in women, when job demands were low (Rothman's synergy index was 2.16 vs. 1.51 when job demands were high). However, in male workers, while a strong synergistic effect between job control and social support at work was found when job demands were low (synergy index was 9.25), there was an antagonistic effect when job demands were high (synergy index was 0.52).
  
  
  CONCLUSIONS
  There was a synergistic interaction effect between job control and social support at work on general psychological distress, but the synergistic effect or its effect size differed by the level of job demands and gender. An atomic, additive approach to the risk assessment of the psychosocial work characteristics on common mental disorders could be misleading or lead to a risk underestimation.
authors.affiliation: Center for Occupational and Environmental Health, University of California Irvine, 5201 California Avenue, Suite 100, Irvine, CA 92617, USA. b.choi@uci.edu
authors.forename: Bongkyoo
authors.initials: B
authors.lastname: Choi
authors.forename: Per-Olof
authors.initials: PO
authors.lastname: Östergren
authors.forename: Catarina
authors.initials: C
authors.lastname: Canivet
authors.forename: Mahnaz
authors.initials: M
authors.lastname: Moghadassi
authors.forename: Sara
authors.initials: S
authors.lastname: Lindeberg
authors.forename: Robert
authors.initials: R
authors.lastname: Karasek
authors.forename: Sven-Olof
authors.initials: SO
authors.lastname: Isacsson
mesh_terms: D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D007588:Job Satisfaction; D008297:Male; D001523:Mental Disorders; D008875:Middle Aged; D016273:Occupational Exposure / Q000009:adverse effects*; D012944:Social Support; D013315:Stress, Psychological; D013548:Sweden