July 28, 2020

expert reaction to systematic review and meta-analysis of studies looking at the association between lithium in drinking water and suicide rates

A study, published in British Journal of Psychiatry, reviewed studies looking at the association between lithium in drinking water and suicide rates.

Professor Keith Hawton, Director, Centre for Suicide Research, University Department of Psychiatry, University of Oxford, said:

“The authors of this review have brought together and analysed findings from several studies which have examined whether lithium in water supplies might have beneficial effects on suicide rates, in keeping with reasonably strong evidence from clinical trials and epidemiological evaluations of lithium therapy in people with mood disorders, especially bipolar disorder. The amounts of lithium in water supplies are tiny compared with when lithium is used as a therapeutic drug. Nevertheless, the reasonable consistency of the review results with those of clinical trials and epidemiological studies of clinical populations is rather persuasive that levels of lithium in water supplies might exert a positive effect on population suicide rates, especially as the findings were stronger in areas with higher suicide rates. The search strategy and review methodology seem very reasonable. The authors also highlight the possible weaknesses of their study, including the fact that naturalistic research designs as used in all the investigations in their review so cannot provide definitive results, only suggestive ones. One issue not raised by the authors is possible toxic effects of lithium, although at the levels found in water supplies these are unlikely to be a major issue. Suicide prevention is a complex and challenging problem. Although, contrary to what the authors say, suicide rates in many countries have been declining in recent years (at least until recently), the toll of the tragic loss of life to suicide globally means that suicide prevention must be continue to be a priority in nations across the world. Whether the results of this review truly indicate a potentially useful element for suicide prevention policy remains unclear. Nevertheless, there would appear to be grounds for further investigating whether supplementing lithium levels in domestic water supplies could help to prevent some deaths, especially in countries with higher suicide rates.”

‘Association between naturally occurring lithium in drinking water and suicide rates: systematic review and meta-analysis of ecological studies’ by Anjum Memon et al. was published in British Journal of Psychiatry on Monday 27^th July.

DOI: https://doi.org/10.1192/bjp.2020.128

Declared interests

None received.