Lithium in drinking water and suicide prevention: The largest nationwide epidemiological study from Japan

Prevention of suicidal behavior with lithium treatment in patients with recurrent mood disorders

Suicidal behavior is more prevalent in bipolar disorders than in other psychiatric illnesses. In the last thirty years evidence has emerged to indicate that long-term treatment of bipolar disorder patients with lithium may reduce risk of suicide and attempts, with possibly similar benefits in recurrent major depressive disorder. We review and update selected research literature on effects of lithium treatment in reducing suicidal behavior and consider proposals that higher levels of lithium in drinking water may be associated with lower suicide rates. We summarize results of a growing number of randomized, controlled studies of lithium treatment for suicide prevention including comparisons with placebos or alternative treatments, and comment on the severe challenges of such trials. The basis of a proposed protective effect of lithium against suicidal behaviors remains uncertain but may include protective effects against recurrences of depressive phases of mood disorders, especially with mixed features or agitation, and possibly through beneficial effects on impulsivity, agitation and dysphoric mood.

Regional disparities in suicide among patients with cancer: A nationwide population-based study in Japan

BACKGROUND

This study aimed to explore prefecture-level differences in suicide risk among patients with cancer in Japan.

METHODS

Data from the National Cancer Registry, which covers the entire Japanese population, were used. Patients diagnosed with cancer between 2016 and 2017 were included. The standardized mortality ratio (SMR) for suicide within 2 years after cancer diagnosis was quantified compared with the general population for each prefecture. Multivariate Poisson regression analysis was conducted to quantify the adjusted relative risk using Hokkaido as the reference.

RESULTS

The analysis included 2,133,502 patients. The SMRs were high among patients with cancer residing in certain prefectures, such as the Hokuriku region (the middle and western parts of Japan's main island). These areas also exhibited a significant relative risk in the Poisson regression model.

CONCLUSION

The results demonstrated that patients with cancer in certain prefectures in Japan have a high suicide risk.

Guide de prescription psychiatrique pendant la grossesse, le postpartum et l’allaitement

Perinatal psychopharmacology is an emerging specialty that is gradually developing alongside perinatal psychiatry. The management of psychiatric disorders during the perinatal period is a challenge for perinatal practitioners due to the multiple changes occurring during this crucial period. This little-known specialty still suffers from inappropriate considerations on the impact of psychotropic treatments on the mother and the infant during pregnancy and postpartum, which can promote a deficiency in perinatal psychic care. However, the risks associated with insufficient management of mental health are major, impacting both the mental and physical health of the mother and the infant. In this paper, we propose a perinatal psychopharmacology prescription guide based on available scientific evidence and international and national recommendations. We thus propose a decision-making process formalized on simple heuristics in order to help the clinician to prescribe psychotropic drugs during the perinatal period.

An investigation into the association between suicide mortality rate and lithium levels in potable water: a review study

This study aimed to investigate the association between lithium levels in potable water and suicide mortality rates in the total inhabitants. We systematically searched Embase, PubMed/MEDLINE, Scopus, PubMed Central (PMC), Google Scholar databases, as well as medRxiv using the following keywords: drinking water, lithium, standardized mortality ratio (SMR), tap water, suicide, and ground water. Pearson regression analysis was used to test an association between variables with 95% confidence interval (CI). A value of P < 0.05 was considered significant. A total of 16 eligible articles were identified. Lithium concentrations in drinking water range from 0.4 to 32.9 μg/l. Average rates of suicide mortality (per 100 000 capita) range between 0.790 (±0.198) and 123 (±50). About 16 original studies confirmed the inverse relationship between lithium concentrations in potable water and suicide mortality rates (R = -0.576; R2 = 0.3323; 95% CI, -0.820 to -0.325; β = -0.3.2; P = 0.019). High lithium concentrations in potable water were associated with decreased suicide rates. We concluded that lithium concentration in potable water was inversely associated with suicide mortality rates among a total population. However, further research is required to clarify the relationship between lithium concentrations in drinking water and suicide rate.

Lithium in drinking water and Alzheimer's dementia: Epidemiological Findings from National Data Base of Japan

OBJECTIVES

The aim of this study was to investigate the association between lithium levels in drinking water and prevalence of Alzheimer's dementia (AD).

METHODS

Lithium levels in the drinking water of 808 cities and wards (i.e., 785 Japanese cities of 46 prefectures and 23 wards of Tokyo) in Japan were examined in relation to the prevalence of AD during the 5 years from 2010 to 2014, which was calculated on the basis of the national data base of Ministry of Health, Labor, and Welfare of Japan. Multiple regression analyses were used to investigate the association of lithium levels with the prevalence of AD with adjustment for relevant factors (proportions of one-person households as a family factor and people in primary industry employment as a job factor, annual total sunshine hours as a meteorological factor, and total number of beds of psychiatric hospitals as a medical factor) in total, male, and female elderly populations.

RESULTS

The adjusted model showed a significant inverse association of lithium levels with female, but not with male, or total prevalence of AD.

CONCLUSIONS

These findings suggest that higher lithium levels in drinking water may be associated with lower prevalence of AD in female, but not male, populations.

Comparison of lithium levels between suicide and non-suicide fatalities: Cross-sectional study

Ecological studies have suggested the protective effect of micro-dose lithium in drinking water against suicide, however, the association between body lithium level and suicide is unknown. We aimed to compare body lithium levels between suicide and non-suicide fatalities. This cross-sectional study included 12 suicides and 16 non-suicides who were examined or dissected at the Tokyo Medical Examiner's Office from March 2018 to June 2021. The aqueous humor lithium concentration was measured twice using inductively coupled plasma mass spectrometry. Analysis of covariance (ANCOVA) was used to compare the lithium concentration between suicides and non-suicides. Mixed-effects model was conducted to account for all lithium concentration data. The aqueous humor lithium concentration did not change after death (t(7) = -0.70, [Formula: see text], SE = 0.03, 95% CI = [-0.09, 0.05], P = 0.51, Cohen's d = 0.01). The aqueous humor lithium concentration was lower in suicides (mean 0.50 μg/L (variance s² 0.04)) than in non-suicides (mean 0.9² μg/L (s² 0.07)) (t(26) = 4.47, [Formula: see text], SE = 0.09, 95% CI = [0.22 to 0.61], P < 0.001, Cohen's d = 1.71). The ANCOVA showed that death by suicide was significantly associated with lower lithium concentration (F(1, 24) = 8.57, P = 0.007), and the effect size was large (η_p² = 0.26). The random intercept model showed a significant effect of suicide on aqueous humor lithium concentration (b = -0.261, SE = 0.102, 95% CI = [-0.471 to -0.051], t(24) = -2.568, P = 0.017). The results of this study demonstrate that even micro-dose lithium is associated with suicide death. Clinical studies are warranted to examine the effects of micro-dose lithium on suicide prevention.

Investigation of the association between lithium levels in drinking water and suicide mortality in Hungary

BACKGROUND

In recent decades, a series of ecological studies from various countries have attempted to reveal whether there is an association between trace amounts of lithium in drinking water and suicide mortality. With some notable exceptions, results have indicated that there is an inverse association between these two variables. Since Hungary had extremely high rates of suicide with a persistent spatial pattern, we consider that our country is ideal to investigate this research question.

METHODS

We carried out our research on Hungarian data at the level of districts (n = 197). The dependent variable was the age- and gender-standardized mortality ratio for suicide (sSMR). Our main explanatory variable was the tap water lithium level (Li) from public drinking water supply systems using their own water source (n = 1 325). Those data, which give full national coverage, were aggregated to the level of districts. Confounding factors were religiosity, alcohol consumption and income. Various regression models were used for statistical calculations.

RESULTS

Findings from our most appropriate regression model - adjusted for relevant confounding variables and able to handle spatial autocorrelation and heteroscedasticity - suggest a significant (p < 0.05) and a trend-like (p < 0.1) negative association between Li and sSMR in the total population and among males, respectively. However, such an association was not found between these two variables among females.

CONCLUSION

In line with the majority of findings from other countries, our results indicate that the intake of lithium with drinking water may have a gender-dependent suicide-protective effect.

Naturally absorbed lithium may prevent suicide attempts and deliberate self-harm while eicosapentaenoic acid may prevent deliberate self-harm and arachidonic acid may be a risk factor for deliberate self-harm: The updated different findings in new analyses

BACKGROUND

Since our previous investigation on the effects of trace lithium, eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA), and arachidonic acid (AA) on deliberate self-harm and suicide attempts in 2018, to our knowledge, no replication study has been conducted on this topic.

SUBJECTS AND METHODS

We increased 37 new patients and totally 234 patients were re-analyzed to further investigate the association of suicide-related behaviors with levels of trace lithium, EPA, DHA, and AA in a different way to avoid multicollinearity.

RESULTS

Higher lithium levels were significantly associated with fewer suicide attempts and deliberate self-harm, higher EPA levels were significantly associated with fewer deliberate self-harm, and higher AA levels were significantly associated with more deliberate self-harm.

DISCUSSION

Although the sample size was only slightly larger than the previous study, the present results were clearly different from the previous ones due to the use of different statistical analyses to avoid multicollinearity.

CONCLUSION

The present findings suggest that naturally absorbed lithium may protect against suicide and deliberate self-harm, while naturally absorbed EPA may protect against deliberate self-harm. However, naturally absorbed AA may be a risk factor for deliberate self-harm.

The Present State of Lithium for the Prevention of Dementia Related to Alzheimer's Dementia in Clinical and Epidemiological Studies: A Critical Review

Despite the unavailability of essential anti-dementia drugs, lithium may inhibit glycogen synthase kinase-3 (GSK-3) and decrease beta-amyloid and hyper-phosphorylated tau. In this review, we hypothesized that trace to standard levels of lithium (i.e., corresponding to the therapeutic levels for bipolar disorder) may be effective for dementia prevention. Excluding three insufficient level studies, we obtained two and one excellent clinical studies on standard and trace lithium levels, respectively, all of which supported the effects of lithium for dementia prevention. In addition, we identified good clinical and epidemiological studies (four each) on standard lithium levels, of which six studies supported the effects of lithium. Moreover, of three good epidemiological studies on trace lithium levels, two supported the aforementioned effects of lithium. The number of studies were substantially small, particularly those on trace lithium levels. Moreover, studies on standard lithium levels were insufficient to establish the efficacy of lithium for dementia prevention. This necessitates accumulating good or excellent clinical evidence for the effects of trace to standard lithium levels on dementia prevention.