Lithium

Lithium in drinking water and suicide mortality

BACKGROUND

There is some evidence that natural levels of lithium in drinking water may have a protective effect on suicide mortality.

AIMS

To evaluate the association between local lithium levels in drinking water and suicide mortality at district level in Austria.

METHOD

A nationwide sample of 6460 lithium measurements was examined for association with suicide rates per 100,000 population and suicide standardised mortality ratios across all 99 Austrian districts. Multivariate regression models were adjusted for well-known socioeconomic factors known to influence suicide mortality in Austria (population density, per capita income, proportion of Roman Catholics, as well as the availability of mental health service providers). Sensitivity analyses and weighted least squares regression were used to challenge the robustness of the results.

RESULTS

The overall suicide rate (R(2) = 0.15, β = -0.39, t = -4.14, P = 0.000073) as well as the suicide mortality ratio (R(2) = 0.17, β = -0.41, t = -4.38, P = 0.000030) were inversely associated with lithium levels in drinking water and remained significant after sensitivity analyses and adjustment for socioeconomic factors.

CONCLUSIONS

In replicating and extending previous results, this study provides strong evidence that geographic regions with higher natural lithium concentrations in drinking water are associated with lower suicide mortality rates.

Review of lithium effects on brain and blood

Clinicians have long used lithium to treat manic depression. They have also observed that lithium causes granulocytosis and lymphopenia while it enhances immunological activities of monocytes and lymphocytes. In fact, clinicians have long used lithium to treat granulocytopenia resulting from radiation and chemotherapy, to boost immunoglobulins after vaccination, and to enhance natural killer activity. Recent studies revealed a mechanism that ties together these disparate effects of lithium. Lithium acts through multiple pathways to inhibit glycogen synthetase kinase-3beta (GSK3 beta). This enzyme phosphorylates and inhibits nuclear factors that turn on cell growth and protection programs, including the nuclear factor of activated T cells (NFAT) and WNT/beta-catenin. In animals, lithium upregulates neurotrophins, including brain-derived neurotrophic factor (BDNF), nerve growth factor, neurotrophin-3 (NT3), as well as receptors to these growth factors in brain. Lithium also stimulates proliferation of stem cells, including bone marrow and neural stem cells in the subventricular zone, striatum, and forebrain. The stimulation of endogenous neural stem cells may explain why lithium increases brain cell density and volume in patients with bipolar disorders. Lithium also increases brain concentrations of the neuronal markers n-acetyl-aspartate and myoinositol. Lithium also remarkably protects neurons against glutamate, seizures, and apoptosis due to a wide variety of neurotoxins. The effective dose range for lithium is 0.6-1.0 mM in serum and >1.5 mM may be toxic. Serum lithium levels of 1.5-2.0 mM may have mild and reversible toxic effects on kidney, liver, heart, and glands. Serum levels of >2 mM may be associated with neurological symptoms, including cerebellar dysfunction. Prolonged lithium intoxication >2 mM can cause permanent brain damage. Lithium has low mutagenic and carcinogenic risk. Lithium is still the most effective therapy for depression. It "cures" a third of the patients with manic depression, improves the lives of about a third, and is ineffective in about a third. Recent studies suggest that some anticonvulsants (i.e., valproate, carbamapazine, and lamotrigene) may be useful in patients that do not respond to lithium. Lithium has been reported to be beneficial in animal models of brain injury, stroke, Alzheimer's, Huntington's, and Parkinson's diseases, amyotrophic lateral sclerosis (ALS), spinal cord injury, and other conditions. Clinical trials assessing the effects of lithium are under way. A recent clinical trial suggests that lithium stops the progression of ALS.

[Lithium gluconate 8% in the treatment of seborrheic dermatitis]

Seborrheic dermatitis is a chronic from of inflammatory dermatitis characterized by erythema and desquamation with predominant localization on the face (nasolabial folds, eyebrows, hair-line and ears). It appears to be caused by proliferation of Malassezia yeasts. Lithium gluconate 8% gel (Lithioderm 8% gel) is the only drug containing topical lithium salt commercially available in France for the treatment of seborrheic dermatitis. The mechanism of action of topical lithium is not well known; it may act through anti-inflammatory and antifungal action. Efficacy and safety were assessed in 2 clinical studies, one versus placebo and the other versus ketoconazole 2% foaming gel using the same principal criterion defined as the rate of patients showing complete remission after 2 months of treatment (complete disappearance of both erythema and desquamation). Lithium gluconate 8% was significantly more effective than placebo and than ketoconazole 2% foaming gel and was well tolerated. Adverse events observed were cutaneous (burning sensation, erythema and pruritus), for the most part of mild severity. No cutaneous side effects contributed to those reported with the use of systemic lithium in psychiatric disorders were noted. Pharmacokinetic studies have shown that systemic absorption after topical application is low. Lithioderm 8% gel is applied twice daily over a recommended period of 2 months. It constitutes a new alternative in the treatment of facial seborrheic dermatitis, regardless of severity.