Does Lithium in Drinking Water Reduce Suicide Rates?

ResearchBlogging.orgLithium has long been used as a psychotherapeutic drug, and treatment with lithium demonstrably reduces incidence of suicide. Lithium also occurs naturally in groundwater to varying degrees. This study explores the relative amount of Lithium in groundwater and suicide in 18 municipalities in Oita prefecture, Japan over a period running from 2002 to 2006. There are two principle findings:

1) There is a negative correlation between standardized (adjusted) suicide rates and the amount of lithium in the water; and

2) It does not take much lithium to produce this effect.

The study reports that the levels of lithium that seem to have this (as yet replicated) effect are much lower than clinical doses used for stabilizing mood and dealing with more serious psychiatric disorders. This would suggest that lithium has a prophylactic effect that is unrelated to its effects as used in more typical situations, or that long term (life long) exposure produces the observed effect.

Here's the pretty picture of the data:

i-da23aad7913eca3b2cb6b9a55fd205b1-lithium_suicice_japan.jpg

You can read the study here.

Ohgami, H., Terao, T., Shiotsuki, I., Ishii, N., & Iwata, N. (2009). Lithium levels in drinking water and risk of suicide The British Journal of Psychiatry, 194 (5), 464-465 DOI: 10.1192/bjp.bp.108.055798

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Nothing like a twofer: the TFH crowd have been flipping out for years over fluoride in drinking water (they even claim it's for mind control!)

I haven't checked MHA lately but am willing to bet that they're already going off on the rumor that LiF will be added to "trank" us all into submission.

By D. C. Sessions (not verified) on 03 May 2009 #permalink

"as yet unreplicated" I would think.

This has to merit further study and soon, yes?

By JohnnieCanuck (not verified) on 03 May 2009 #permalink

It would be interesting to also look at the murder rates.

My math skills are poor... would y'all please help me out? It's a logarithmic scale (for X; linear for Y), which means non-linear. I get that. But the exact meaning of a downward sloping linear regression on a logarithmic scale, I'm having a little trouble wrapping my head around. Does it mean that each incremental increase of lithium had a lesser impact on suicide rates? Or to put it another way, it took more and more added lithium to cause the same incremental decrease in suicide rate as you go to the right on the X axis. Have I got that right?

By Wayne Conrad (not verified) on 04 May 2009 #permalink

Wayne: The second of those two statements would probably be the best way to put it.

However, we also have to consider that the comparison is being made of things that are not of equivalent dimensionality. The Y axis is observed events over unit time, and the X axis is number of molecules of lithium in a volume of water (consumed over time). It is almost like comparing a one dimensional to a three dimensional measure (sort of). My inclination would have been to take the cube root of the lithium value. But I'm strange about dimensionality. I actually try to understand it rather than gloss it with the usual techniques.

Greg, Thanks for the explanation.

Fascinating.

By Wayne Conrad (not verified) on 04 May 2009 #permalink

So in some northern countries it is worth to add some lithum to water as the rate of depression (lithum is used against depression as well) and suicides is the highest due to lack of sun.

But Greg, you don't drink a line of water; you drink a volume of it, which at a given concentration of a solute is a certain number of molecules.

P.S. If you're not part of the solution, you're part of the precipitate!