Lithium has been heralded by some experts as the next potential flouride, after scientists found suicide rates were lower in areas where the drinking water had higher concentrations of the element.

Researchers from the Medical University of Vienna compared the suicide rates in different regions of Austria with the natural lithium concentrations in the drinking water.

The study, published in the British Journal of Pyschiatry, analysed a sample of 6,460 lithium measurements and then compared suicide rates across 99 districts.

In the 10 most lithium-depleted regions in Austria, the suicide rate was 16 per 100,000, but in the 10 most lithium-rich regions the suicide rate was just 11 per 100,000.

‘This should stimulate further research in low-level effects of lithium,’ lead author Dr Nestor Kapusta said.

It confirms research from 2009 that found the same inverse relationship between lithium levels and suicide rates in Japan.

Dr Jacob Appel, from Mount Sinai Hospital in New York, said the latest studies provided ‘compelling’ evidence of the mood-stabilising benefits of lithium.

‘The theory is that lithium in trace amounts enhances the connectivity among neurons and having exposure over a lifetime makes the brain more happy,’ he explained.

He said the U.S already supplemented the drinking water with flouride to prevent tooth decay and it would be relatively easy to add lithium, which is a naturally occurring element.

He added: ‘People who oppose adding lithium to the drinking water in trace amounts don’t go around advocating to strain the lithium from the drinking water from areas where it does exist.

‘Why not give everyone the same benefit?’

Dr Appel is not a lone voice on the subject. The idea was first mooted by Dr Gerhard Schauzer after he was inspired by the ‘miracle spring’ in his home town of Franzenbad in the Czech Republic.

In 1989, Dr Schauzer published a survey that looked at 27 counties in Texas over a decade. He found there was a consistent inverse relationship between lithium levels in water and the suicide, violent crime and rape rate.

But his proposal to supplement water supplies with lithium was not popular.

‘People were convinced I was trying to impose mass mind control,’ he told TheDaily.com.

‘There was widespread ignorance about what lithium does.’

The professor at the University of California in San Diego said he still believed introducing it would be a ‘great initiative.’

‘People today are drinking water this is more and more thoroughly purified, to the point where it is devoid of nutritional benefit,’ he said.

In high doses, lithium is an effective treatment for bipolar disorder. A study published in the British Journal of Psychiatry last month also found it helped slow the progression of memory loss – raising the possibility it could be used to prevent dementia.

However, Dr Appel was keen to stress that only traces of lithium would ever be added to drinking water.

‘We are not talking about therapeutic amounts,’ he said, adding that a person would have to swallow ‘several olympic swimming pools’ of water a day to get a similar dosage to a prescription pill.

His argument may hold greater sway in the U.S where the nationwide fluoridation of water in the 1940s was hailed as a great public health success.

In the UK only 10 per cent of the water is fluoridated, with opponents criticising it as ‘compulsory mass medication.’

When a health trust in Southampton tried to force through the flouridation of tap water in 2009, it caused uproar and a legal wrangle that is ongoing.