Traces of Lithuim in Drinking Water May Have 'Anti-Suicidal Effect'

Traces of the chemical lithium in drinking water have been linked to lower suicide rates in a study.

By looking at 15 existing ecological studies related to lithium and suicide, the authors of a British Journal of Psychiatry study found a "consistent protective" association between the levels and / or concentrations of lithium in drinking water and rates of death by suicide.

The research included in their analysis were carried out in the U.S., Japan, Austria, England, Greece, Italy, and Lithuania, where drinking water samples were compared against official data on suicide deaths. The total populations involved in the respective studies ranged from 1,109,261 to 22,097,948, and the suicide mortality rates per 100,000 per year ranged from 7.53 to 27.

The results suggest the presence of the chemical in drinking water may protect against suicide at a population-wide level, the team said. Putting lithium in the public water for supply may be a way to test the hypothesis, particularly in areas with high levels of mental illness, violent crime, substance misuse, and suicide risk.

The study comes amid increasing rates of suicide and mental illness in "many countries," the team wrote. For instance, a study published last year in the journal JAMA found suicide rates among young people in the U.S. have hit their highest levels in almost two decades. And according to the World Health Organization, close to 800,000 people die by suicide each year, or one person every 40 seconds.

Sometimes called "magic ion," lithium is widely used as a medicine for preventing and treating manic depressive episodes, stabilizing a patient's mood, and lowering the risk of suicide, the team wrote. It is found in vegetables, grains, spices, and in trace amounts in almost all rocks, which is how it finds it way into the public water supply.

Studies dating back to the 1990s have looked at the hypothesis that naturally occurring lithium in drinking water could prevent suicide, the researchers said.

Lead author professor Anjum Memon, chair in epidemiology and public health medicine at Brighton and Sussex Medical School, U.K., said in a statement: "It is promising that higher levels of trace lithium in drinking water may exert an anti-suicidal effect and have the potential to improve community mental health."

Memon said: "In these unprecedented times of COVID-19 pandemic and the consequent increase in the incidence of mental health conditions, accessing ways to improve community mental health and reduce the incidence of anxiety, depression and suicide is ever more important."

Co-author professor Allan Young, chair of mood disorders at the U.K.'s King's College London, said: "The levels of lithium in drinking water are far lower than those recommended when lithium is used as medicine although the duration of exposure may be far longer, potentially starting at conception."

Professor Carmine Pariante of the U.K's Royal College of Psychiatrists who did not work on the paper, said: "This study shows that the boundaries between medication and nutritional interventions are not as rigid as we used to think, opening up the possibility of new treatments that span both domains. More knowledge of the beneficial properties of Lithium and its role in regulating brain function can lead to a deeper understanding of mental illness and improve the wellbeing of patients with depression and other mental health problems."

Professor Keith Hawton, director of the Centre for Suicide Research the U.K.'s University of Oxford who did not work on the study, said in a statement the approach the team took seems "very reasonable."

He said: "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."

A weakness of the study, as highlighted by the team, is that they made no interventions "so cannot provide definitive results, only suggestive ones," he said.

Hawton said the team did not raise the 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 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," Hawton said.

If you have thoughts of suicide, confidential help is available for free at the National Suicide Prevention Lifeline. Call 1-800-273-8255. The line is available 24 hours, every day.