title: The association between green space and depressive symptoms in pregnant women: moderating roles of socioeconomic status and physical activity.
abstract: BACKGROUND
  The current study explored the association between green space and depression in a deprived, multiethnic sample of pregnant women, and examined moderating and mediating variables.
  
  
  METHODS
  7547 women recruited to the 'Born in Bradford' cohort completed a questionnaire during pregnancy. A binary measure of depressive symptoms was calculated using a validated survey. Two green space measures were used: quintiles of residential greenness calculated using the normalised difference vegetation index for three neighbourhood sizes (100, 300 and 500 m buffer zones around participant addresses); access to major green spaces estimated as straight line distance between participant address and nearest green space (>0.5 hectares). Logistic regression analyses examined relationships between green space and depressive symptoms, controlling for ethnicity, demographics, socioeconomic status (SES) and health behaviours. Multiplicative interactions explored variations by ethnic group, SES or activity levels. Mediation analysis assessed indirect effects via physical activity.
  
  
  RESULTS
  Pregnant women in the greener quintiles were 18-23% less likely to report depressive symptoms than those in the least green quintile (for within 100 m of green space buffer zone). The green space-depressive symptoms association was significant for women with lower education or who were active. Physical activity partially mediated the association of green space, but explained only a small portion of the direct effect.
  
  
  CONCLUSIONS
  Higher residential greenness was associated with a reduced likelihood of depressive symptoms. Associations may be stronger for more disadvantaged groups and for those who are already physically active. Improving green space is a promising intervention to reduce risk of depression in disadvantaged groups.
authors.affiliation: Bradford Institute for Health Research, Bradford Teaching Hospitals NHS Foundation Trust, Bradford, UK.
authors.forename: R R C
authors.initials: RR
authors.lastname: McEachan
authors.affiliation: Department of Health Sciences, University of York, York, UK.
authors.forename: S L
authors.initials: SL
authors.lastname: Prady
authors.affiliation: Institute for Environment and Sustainability Research, Staffordshire University, Stoke-on-Trent, UK.
authors.forename: G
authors.initials: G
authors.lastname: Smith
authors.affiliation: Division of Epidemiology and Biostatistics, University of Leeds, Leeds, UK.
authors.forename: L
authors.initials: L
authors.lastname: Fairley
authors.affiliation: Bradford Institute for Health Research, Bradford Teaching Hospitals NHS Foundation Trust, Bradford, UK Faculty of Medicine- Clínica Alemana de Santiago, Universidad del Desarrollo, Santiago, Chile.
authors.forename: B
authors.initials: B
authors.lastname: Cabieses
authors.affiliation: Centre for Sport, Health and Exercise Research, Staffordshire University, Stoke-on-Trent, UK.
authors.forename: C
authors.initials: C
authors.lastname: Gidlow
authors.affiliation: Bradford Institute for Health Research, Bradford Teaching Hospitals NHS Foundation Trust, Bradford, UK.
authors.forename: J
authors.initials: J
authors.lastname: Wright
authors.affiliation: Centre for Research in Environmental Epidemiology (CREAL), Barcelona, Spain.
authors.forename: P
authors.initials: P
authors.lastname: Dadvand
authors.affiliation: Centre for Research in Environmental Epidemiology (CREAL), Barcelona, Spain.
authors.forename: D
authors.initials: D
authors.lastname: van Gent
authors.affiliation: Centre for Research in Environmental Epidemiology (CREAL), Barcelona, Spain.
authors.forename: M J
authors.initials: MJ
authors.lastname: Nieuwenhuijsen
mesh_terms: D000328:Adult; D003863:Depression / Q000175:diagnosis / Q000523:psychology*; D004777:Environment; D004779:Environment Design; D015444:Exercise; D005260:Female; D015438:Health Behavior; D006306:Health Surveys; D006801:Humans; D008137:Longitudinal Studies; D011247:Pregnancy; D037841:Pregnant People / Q000523:psychology*; D012111:Residence Characteristics / Q000706:statistics & numerical data*; D012923:Social Class; D012959:Socioeconomic Factors; D011795:Surveys and Questionnaires
keywords: DEPRESSION; DEPRIVATION; ETHNICITY; Environmental epidemiology; PREGNANCY