Citation

Rihmer Z, Döme P. Eur. Neuropsychopharmacol. 2023; 71: 3-5.

Copyright

(Copyright © 2023, Elsevier Publishing)

DOI

10.1016/j.euroneuro.2023.02.009

PMID

36867985

Abstract

Lithium (Li) is the oldest psychotropic agent for the treatment of mood disorders and one that is still used. Li has several therapeutic indications including phase prophylaxis and treatment of acute mania in bipolar disorder, as well as augmentation of the efficacy of antidepressants and prevention of recurrence of major depressive disorder (Izsak et al., 2022). Despite its well-established efficacy, Li is dramatically underutilized in several countries (Bauer, 2022; Rybakowski, 2022). Taking into consideration the beneficial effects of Li in patients with mood disorders and the fact that one of the most powerful risk factors for suicide is (untreated) major depressive episode, the conclusion lies close at hand that Li may have antisuicide properties (Cipriani et al., 2013; Rihmer, 2007). Furthermore, the anti-impulsive and anti-aggressive properties of Li may also contribute to its antisuicidal effects (Cipriani et al., 2013; Eyre-Watt et al., 2021; Izsak et al., 2022). The antisuicide properties of Li in clinical samples of mood-disorder patients are supported by meta-analyses (MA) (Cipriani et al., 2013; Wilkinson et al., 2022). Contrary to expectations, a very recent MA was unable to replicate these results. However, that paper was extensively criticized subsequently for various methodological shortcomings (Bschor et al., 2022).

In addition to the aforementioned favourable central nervous system effects of Li in clinical doses, results of 2 randomized controlled trials have suggested that microdose (i.e. doses in the order of 100 μg/day) Li administration is also neuroactive and has beneficial impacts on the progression of cognitive decline in patients with Alzheimer's disease and improved and stabilized the mood of former drug users (Izsak et al., 2022).

RESULTS of two other studies using individual-level data have also suggested that low-level (nutritional) Li intake may have neuroactive (specifically anti-aggressive) properties. In one of these studies, Li content of the hair (reflecting the levels of dietary Li intake over the preceding weeks to months) was threefold higher in healthy men than in violent offenders, while in the other study an inverse association was found between urine Li levels (which was positively correlated with drinking water Li levels) and homicide rate in the population (Hidvégi et al., 2016). Bioactive properties of trace amounts of Li are also supported by results indicating a relationship between drinking water Li levels and compromised thyroid functions (Eyre-Watt et al., 2021).

The estimated Li intake from foods and beverages is between a few hundred and a few thousand μg/day (Hidvégi et al., 2016). Accordingly, Li exposure from drinking tap water is several orders of magnitude less than the therapeutic...

Language: en

Keywords

Prevention; Suicide; Lithium; Drinking water; Tap water