Effect of pesticide ban on suicide trend – a 20-year study from a tertiary care center in Central Kerala from 2001 to 2020

<b>Introduction:</b> We assessed the effect of the pesticide regulations implemented in 2011 on suicide trend in Kerala state of India. <b>Materials and methods:</b> Data were collected from case records of suicide autopsies done in a single tertiary care hospital in Thrissur district of Kerala in 2001–2020. Linear trends in overall suicide rates were identified using joinpoint regression analysis. We used Poisson regression models to estimate the annual expected number of suicides in 2011–2020 and calculated the rate ratios between the observed number of suicide and that expected according to the linear pre-ban suicide trend (2005–2010). <b>Results:</b> There were a total of 14,593 suicide autopsies (2501 pesticide autopsies) in 2001-2020. Carbofuran was the commonest pesticide identified, followed by quinalphos, zinc phosphide, and chlorpyrifos. In 2011–2020, overall suicide rates were 22%–48% and pesticide suicide rates were 20%–55% lower than those expected according to pre-ban suicide trends (2005–2010), with the only exception of a 16% higher-than-expected pesticide suicide rate in 2011. There was no change in trend in hanging suicides. <b>Conclusion:</b> Lower-than-expected overall and pesticide suicide rates were found in Thrissur district after the 2011 bans of pesticides in Kerala, with no evidence of means replacement to hanging.