Correlation between lithium concentrations in drinking water and suicide attempt in the southeast of Iran

Suicide, as an avoidable cause of death in public health systems, currently lacks effective global strategies to prevent it. However, several epidemiological studies found a correlation between the concentration of lithium (Li) in drinking water and lower suicide rates in the general population. Our ecological study investigated this hypothesis in the Rafsanjan district of Iran. Samples from the public water supply in 16 areas in the district were analyzed using the graphite furnace atomic absorption. The resulting data were examined in relation to the suicide attempt from March 2019 to March 2020 obtained from Iran's Ministry of Health's registration system. During that period, 239 suicide attempts were recorded, resulting in an average of 69 individuals (85 women and 54 men) per 100,000 residents of the area. The average Li concentration in the drinking water was 47.30 µg/L (ranging from 9.4 to 141 µg/L). A negative significant correlation (r = -0.551, p = 0.027) between Li concentration in water and the rate of suicide attempt were observed in the studied population. Notably, these findings indicate an inverse significant relationship between Li levels and suicide attempt rate in women (r = -0.725, p = 0.001). This is the first study in Iran that examines the relationship between Li levels in drinking water and suicide attempt rate. The findings of this study support an inverse relationship between the level of Li in public drinking water and the rate of women suicide attempt.