Household Drinking Water Conditions and Depressive Symptoms among Adults Aged 45 Years and Older in India: Evidence from the Longitudinal Ageing Study in India (LASI) Wave-1

Background Access to safe, reliable, and accessible drinking water is an important component of household well-being and may have implications for mental health. Although previous studies have reported associations between water-related conditions and depression, evidence among middle-aged and older adults in India remains limited. This study examined the association between poor household drinking-water conditions and depressive symptoms among adults aged 45 years and above in India. Methods We analysed cross-sectional data from the Longitudinal Ageing Study in India (LASI) Wave 1 (2017–18), including 60,512 adults aged 45 years and above. Depressive symptoms were assessed using the 10-item Centre for Epidemiological Studies Depression (CES-D-10) scale, with a score of ≥ 4 indicating depressive symptoms. Because LASI does not contain a validated household water-insecurity scale, we constructed a transparent five-item household drinking-water conditions index from source type, source location, one-way collection time, daily collection-trip frequency, and household water-treatment practice. Each indicator was coded 0/1 and summed (0–5); a binary exposure classified any household with at least one poor condition as having a higher burden of poor drinking-water conditions. Logistic regression models were estimated to assess the association after adjustment for sociodemographic and contextual covariates. Component-specific and continuous-index analyses were used as sensitivity analyses. Results Exposure to poor drinking-water conditions was significantly associated with higher odds of depressive symptoms in the unadjusted model (OR = 1.577, 95% CI: 1.512–1.645). This association remained statistically significant following adjustment for sociodemographic and contextual characteristics (OR = 1.203, 95% CI: 1.144–1.265). In the component-specific analysis, water-collection time exceeding 15 minutes per one-way trip (OR = 1.241, 95% CI: 1.153–1.335) and the absence of household drinking-water treatment (OR = 1.195, 95% CI: 1.142–1.251) were independently associated with higher odds of depressive symptoms. In contrast, water-source location, frequency of water collection, and water-source type were not independently associated with depressive symptoms. Furthermore, each one-unit increase in the composite poor drinking-water conditions score was associated with an 8.1% increase in the odds of depressive symptoms (OR = 1.081, 95% CI: 1.061–1.101). Conclusions In India in 2017–18, poor household drinking-water conditions were associated with depressive symptoms among adults aged 45 years and older. The findings are consistent with the hypothesis that collection burden and water-safety-related conditions may be relevant to mental health, but the cross-sectional design and the proxy nature of the exposure preclude causal or mechanistic conclusions. Future studies should use validated water-insecurity measures, directly assess intermediate pathways and functional status, and examine changes following improvements in drinking-water services. Clinical Trial Registration Not applicable.