title: Green qualities in the neighbourhood and mental health - results from a longitudinal cohort study in Southern Sweden.
abstract: BACKGROUND
  Poor mental health is a major issue worldwide and causality is complex. For diseases with multifactorial background synergistic effects of person- and place- factors can potentially be preventive. Nature is suggested as one such positive place-factor. In this cohort study we tested the effect of defined green qualities (Serene, Space, Wild, Culture, Lush) in the environment at baseline on mental health at follow-up. We also studied interaction effects on mental health of those place factors and varied person factors (financial stress, living conditions, and physical activity).
  
  
  METHODS
  Data on person factors were extracted from a longitudinal (years 1999/2000 and 2005) population health survey (n = 24945). The participants were geocoded and linked to data on green qualities from landscape assessments, and stored in the Geographical Information System (GIS). Crude odds ratios (OR) and 95% confidence intervals (CI) were calculated, and multivariate logistic analyses were performed.
  
  
  RESULTS
  Mental health was not affected by access to the chosen green qualities, neither in terms of amount nor in terms of any specific quality. However, we found a reduced risk for poor mental health at follow-up among women, through a significant interaction effect between physical activity and access to the qualities Serene or Space. For men the tendencies were similar, though not significant. Regarding the other three green qualities, as well as amount of qualities, no statistically certain synergistic effects were found. Likewise, no significant synergies were detected between green qualities and the other person-factors. Only advanced exercise significantly reduced the risk for poor mental health among women, but not for men, compared to physical inactivity.
  
  
  CONCLUSIONS
  The results do not directly support the hypothesis of a preventive mental health effect by access to the green qualities. However, the additive effect of serene nature to physical activity contributed to better mental health at follow-up. This tendency was equal for both sexes, but statistically significant only for women.Objective landscape assessments may be important in detangling geographic determinants of health. This study stresses the importance of considering interaction effects when dealing with disorders of multifactorial background.
authors.affiliation: Faculty of Landscape Planning, Horticulture, and Agricultural Sciences, Department of Work Science, Business Economics and Environmental Psychology, Swedish University of Agricultural Sciences, Alnarp, Sweden. Matilda.annerstedt@slu.se
authors.forename: Matilda
authors.initials: M
authors.lastname: Annerstedt
authors.forename: Per-Olof
authors.initials: PO
authors.lastname: Ostergren
authors.forename: Jonas
authors.initials: J
authors.lastname: Björk
authors.forename: Patrik
authors.initials: P
authors.lastname: Grahn
authors.forename: Erik
authors.initials: E
authors.lastname: Skärbäck
authors.forename: Peter
authors.initials: P
authors.lastname: Währborg
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D015331:Cohort Studies; D039721:Diagnostic and Statistical Manual of Mental Disorders; D004779:Environment Design; D015444:Exercise / Q000523:psychology*; D005260:Female; D005382:Financing, Personal; D006305:Health Status Indicators; D054625:Healthcare Disparities; D006801:Humans; D016015:Logistic Models; D008137:Longitudinal Studies; D008297:Male; D001523:Mental Disorders / Q000453:epidemiology / Q000209:etiology / Q000523:psychology; D008603:Mental Health / Q000706:statistics & numerical data; D008875:Middle Aged; D012111:Residence Characteristics; D012737:Sex Factors; D012924:Social Conditions; D012937:Social Mobility / Q000191:economics / Q000706:statistics & numerical data; D012959:Socioeconomic Factors; D013315:Stress, Psychological / Q000453:epidemiology; D011795:Surveys and Questionnaires; D013548:Sweden