Too early to add lithium to drinking water? No association between lithium and suicides in a pre-registered Swiss study.

Journal: Journal Of Affective Disorders
Published:
Abstract

Background: Suicide remains a significant public health concern worldwide. Ecological studies reported decreased suicide rates with higher levels of trace lithium levels in drinking water, leading to suggestions of adding lithium to drinking water as a preventative anti-suicide strategy. However, the evidence remains inconclusive, and thus more data are needed.

Methods: This pre-registered study analyzed the association between lithium concentrations in drinking water and suicide rates across 1043 municipalities in Switzerland between 1981 and 2021. We used bivariate correlation analysis, ordinary regression models, and spatial regression models, while accounting for potential confounding variables.

Results: There were no significant associations between lithium levels in drinking water and suicide rates, as determined by correlation analysis (r = -0.03, 95 % CI -0.09-0.03, p = 0.33), and by multivariable ordinary and spatial regression models.

Conclusions: The correlation between levels of lithium in tap water and the serum of individuals is unknown and ecological studies are inherently limited to establish a causal association. Conclusions: The null finding in our study adds to the ongoing debate on the effectiveness of trace lithium in drinking water as a public health intervention for suicide prevention, indicating that calls for lithium supplementation are still premature. These findings highlight the need for further research with transparent and replicable methodologies to clarify the potential role of lithium in suicide prevention.

Authors
Eva-maria Pichler, Clemens Fartacek, Benjamin Miller Doebeling, Marc Walter, Martin Plöderl