Extremes in water availability and suicide: Evidence from a nationally representative sample of rural Indian adults

Background: Extremes in water availability, either exceptionally wet or dry conditions, can damage crops and may detrimentally affect the livelihood and well-being of people engaged in agriculture. We estimated the effect of water availability on suicide in rural India, a context where the majority of households are dependent upon agriculture. Methods: We used data from a nationally representative sample of 8.5 million people who were monitored for causes of death from 2001 to 2013. Water availability was measured with high-resolution precipitation and temperature data (i.e., the Standardized Precipitation Evapotranspiration Index). We used a fixed effects approach that modeled changes in water availability within districts (n = 569) over time (n = 13 years) to estimate the impact on suicide deaths. We restricted our analysis to rural areas and to deaths occurring during the growing season (June–March) among adults aged 15 or older, and controlled for sex, age, region, and year. We used Poisson regression with standard errors clustered at the district level and total deaths as the offset. Results: There were 9456 suicides and 249,786 total deaths in our study population between 2001 and 2013. Compared to normal growing seasons, the percent of deaths due to suicide increased by 18.7% during extremely wet growing seasons (95% CI: 6.2, 31.2) and by 3.6% during extremely dry growing seasons (95% CI: −17.9, 25.0). We found that effects varied by age. Conclusions: We found extremes is water availability associated with an increase in suicide. Abnormally wet growing conditions may play an important, yet overlooked, role in suicide among rural Indian adults.