Speaker
Description
The global population aging trend necessitates a deeper understanding of factors influencing older adults' physical and emotional well-being. Mental health disorders, particularly depression, are a critical concern in this vulnerable demographic group, per the WHO. While past studies indicate an association between participation in outdoor physical activity and improved mental health conditions, establishing a causal connection, while critical for policymaking, is complicated by endogeneity (Yemiscigil and Vlaev, 2021). A bidirectional physical activity – mental health relationship may exist due to: 1) the development of depression owing to lack of physical activity, 2) the lack of engagement in physical activity among individuals experiencing depression, or 3) the use of physical activity as a coping mechanism by certain individuals having depressive symptoms. The endogeneity problem leads to a biased and inefficient estimate of the true effect of physical activity on depression. Our study addresses this issue by exploring the causal link between neighborhood environment (physical and social) and mental health using a unique dataset from India and by employing the two-stage least squares (2SLS) regression approach. We use the Longitudinal Aging Study in India (LASI), a nationwide survey conducted for the scientific investigation of the health, economic, and social characteristics of older adults. The LASI Wave 1 (2017-18) covers all 30 states and six Union Territories of India with a sample size of over 72,000 persons aged 45 years and above. We consider over 27,000 older adults aged 60 years or more living in urban and rural areas across India in our study. We identify two instrumental variables (IVs) that can theoretically influence outdoor physical activity participation but not depression directly (except through their impact on outdoor physical activity): household market value (a proxy for neighborhood quality and socioeconomic status) and park proximity (Chang, 2020). Our IV-based approach allows us to isolate the causal effect of physical activity on depression despite the potential for a bi-directional connection. We find both instruments to be significantly positively associated with outdoor physical activity (the first stage) and that they can be used as valid IVs. Our 2SLS estimates reveal a robust and causally significant negative association between frequent outdoor physical activity (at least once per week) and depression. Frequent outdoor physical activity is associated with an 11-point reduction in the CES-D (Center for Epidemiologic Studies Depression Scale) score and a significant decrease in the probability of experiencing depression, after controlling for potential confounders. We make a significant contribution to the literature by isolating the effect of outdoor physical activity participation driven by factors external to an individual’s mental state, which provides strong evidence for a causal pathway from increased outdoor physical activity to reduced depression among older adults. Moreover, existing studies have overwhelmingly focused on developed countries, leaving evidence from the developing world scant. Our findings have significant implications for urban planning and policy in developing countries like India, highlighting the importance of creating age-friendly environments that prioritize neighborhood quality and access to green spaces (Lu and Peng, 2019). Our research provides a model for future urban research investigating complex causal relationships where endogeneity is a concern.
References
Chang, P.J., 2020. Effects of the built and social features of urban greenways on the outdoor activity of older adults. Landscape and Urban Planning, 204, p.103929.
Lu, N. and Peng, C., 2019. Community-based structural social capital and depressive symptoms of older urban Chinese adults: The mediating role of cognitive social capital. Archives of gerontology and geriatrics, 82, pp.74-80.
Yemiscigil, A. and Vlaev, I., 2021. The bidirectional relationship between sense of purpose in life and physical activity: a longitudinal study. Journal of Behavioral Medicine, 44(5), pp.715-725.
| Keywords | Older adults; Vulnerable populations; Mental health; Physical activity; Built environment |
|---|---|
| Best Congress Paper Award | Yes |
