Gesundheitswesen 2016; 78 - A69
DOI: 10.1055/s-0036-1586579

Urban residential greenness and repeated measurements of depressive symptoms: results from the Heinz Nixdorf Recall study

E Orban 1, R Sutcliffe 1, U Roggenbuck 2, N Dragano 3, KH Jöckel 2, S Moebus 1, 2
  • 1Zentrum für Urbane Epidemiologie (CUE), Institut für Medizinische Informatik, Biometrie und Epidemiologie (IMIBE), Universitätsklinikum der Universität Duisburg-Essen, Essen
  • 2Institut für Medizinische Informatik, Biometrie und Epidemiologie (IMIBE), Universitätsklinikum der Universität Duisburg-Essen, Essen
  • 3Institut für Medizinische Soziologie, Universitätsklinikum Düsseldorf, Heinrich Heine Universität Düsseldorf, Düsseldorf

Background: Previous research suggests that access to green spaces, contact with nature and outdoor physical activity may benefit mental health; however, only limited evidence exists from population-based and longitudinal data. Our aim was to investigate the association between urban residential greenness and depressive symptoms.

Methods: We analyzed data of 4,662 participants from the population-based Heinz Nixdorf Recall study, aged 45 – 75 years and residing in the metropolitan Ruhr area, Germany. Baseline examinations took place in 2000 – 2003, with follow-up examinations after five and ten years. Additionally, participants received annual mailed follow-up questionnaires.

Level of greenness within a 100-meter buffer of each participant's baseline residence was defined by the Normalized Difference Vegetation Index (NDVI, range: 0 – 1), which was calculated from satellite imagery using a geographic information system. Low residential greenness was defined through the lowest NDVI quartile (< 0.30).

Depressive symptoms were assessed by the CES-D 15-item questionnaire at baseline and follow-up years 5 through 13, resulting in up to nine measurements per participant. A CES-D score ≥17 at all measurements and/or intake of antidepressant medication at all visited examinations were classified as depressive symptoms.

Odds ratios (OR) and 95% confidence intervals (95% CI) were calculated by logistic regression, adjusting for age, sex, economic activity, neighborhood socioeconomic status, traffic noise, co-morbidities, BMI and smoking.

Results: In our study, values of the NDVI ranged from 0.02 – 0.66. Depressive symptoms were observed in 6.6% of women and 3.7% of men. Among participants with high and low greenness the percentages were 4.6% and 6.9%, respectively. The adjusted OR of depressive symptoms was 1.34 (95% CI 0.99 – 1.81; crude OR: 1.53, 1.16 – 2.02) comparing those with low greenness to those with higher greenness. Sex-stratified analyses suggest higher effects in women (adjusted OR: 1.52, 1.04 – 2.21; men: 1.05, 0.62 – 1.79).

Conclusion: Our study reveals an association between low greenness and depressive symptoms. Evidence from additional studies is needed as well as exploring the influence of the quality of green. This knowledge is valuable for urban planners in developing strategies for creating a healthy urban environment.