March 12, 2024

A recent SALURBAL study published in Applied Geography sheds light on the relationship between neighborhood greenness and mental health and depression in cities across Mexico. The study, “Associations between urban greenspace and depressive symptoms in Mexico's cities using different greenspace metrics,” was conducted by an interdisciplinary team of researchers from the Urban Health in Latin America (SALURBAL) Project led by Maryia Bakhtsiyarava, a postdoctoral scholar from the University of California, Berkeley. The research contributes much-needed evidence of the importance of urban greening and greenspace on health in rapidly urbanizing regions across the global south.

The authors examined connections between neighborhood greenspace and depressive symptoms among more than 17,000 urban residents in 84 large cities across Mexico. Key findings indicate that higher levels of neighborhood “greenness” (measured using the Normalized Difference Vegetation Index or NDVI) were associated with almost 10% lower odds of experiencing depressive symptoms.

The authors emphasize the importance of routinely utilizing multiple complementary greenspace metrics in research. For example, even though they are both often used to describe greenness, NDVI and percent greenspace are different metrics and provide complementary information about greenspace. NDVI can help capture information about the vigor of vegetation in an area, while percent greenspace only indicates overall coverage. In the study, the percentage of greenspace in neighborhoods was not associated with any changes in depressive symptoms.

“These findings emphasize the importance of routinely utilizing multiple, complementary greenspace metrics for our research. Although these metrics are strongly correlated, they are not necessarily interchangeable,” says Dr. Bakhtsiyarava, lead author of the study.

Findings from the study also suggest that environmental factors may influence the potential for greenspace to positively contribute to mental health. For example, air pollution (PM2.5) may limit the benefits of greenspace for mental wellbeing.

“As the world grapples with the many challenges posed by rapid urbanization and mental health concerns, studies should be careful in evaluating which specific characteristics of greenspace can contribute to human wellbeing within the framework of building healthy, sustainable cities,” adds Dr. Bakhtsiyarava.

This research was made possible with support from the Wellcome Trust. Read the full study: Associations between urban greenspace and depressive symptoms in Mexico's cities using different greenspace metrics