The prevalence of mental health conditions and national suicide rates are increasing in many countries. Lithium is widely and effectively used in pharmacological doses for the treatment and prevention of manic/depressive episodes, stabilising mood and reducing the risk of suicide. Since the 1990s, several ecological studies have tested the hypothesis that trace doses of naturally occurring lithium in drinking water may have a protective effect against suicide in the general population.

To synthesise the global evidence on the association between lithium levels in drinking water and suicide mortality rates.

The MEDLINE, Embase, Web of Science and PsycINFO databases were searched to identify eligible ecological studies published between 1 January 1946 and 10 September 2018. Standardised regression coefficients for total (i.e. both genders combined), male and female suicide mortality rates were extracted and pooled using random-effects meta-analysis. The study was registered with PROSPERO (CRD42016041375).

The literature search identified 415 articles; of these, 15 ecological studies were included in the synthesis. The random-effects meta-analysis showed a consistent protective (or inverse) association between lithium levels/concentration in publicly available drinking water and total (pooled β = −0.27, 95% CI −0.47 to −0.08; P = 0.006, I2 = 83.3%), male (pooled β = −0.26, 95% CI −0.56 to 0.03; P = 0.08, I2 = 91.9%) and female (pooled β = −0.13, 95% CI −0.24 to −0.02; P = 0.03, I2 = 28.5%) suicide mortality rates. A similar protective association was observed in the six studies included in the narrative synthesis, and subgroup meta-analyses based on the higher/lower suicide mortality rates and lithium levels/concentration.

This synthesis of ecological studies, which are subject to the ecological fallacy/bias, supports the hypothesis that there is a protective (or inverse) association between lithium intakes from public drinking water and suicide mortality at the population level. Naturally occurring lithium in drinking water may have the potential to reduce the risk of suicide and may possibly help in mood stabilisation, particularly in populations with relatively high suicide rates and geographical areas with a greater range of lithium concentration in the drinking water. All the available evidence suggests that randomised community trials of lithium supplementation of the water supply might be a means of testing the hypothesis, particularly in communities (or settings) with demonstrated high prevalence of mental health conditions, violent criminal behaviour, chronic substance misuse and risk of suicide.

Mental disorders are associated with an elevated risk for suicide attempt and suicide. Whether the strength of the associations also holds for refugees is unclear.

To examine the relationship between specific mental disorders and suicide attempt and suicide in refugees and Swedish-born individuals.

This longitudinal cohort study included 5 083 447 individuals aged 16–64 years, residing in Sweden in 2004, where 196 757 were refugees. Mental disorders were defined as having a diagnosis in psychiatric care during 2000–2004. Estimates of risk of suicide attempt and suicide were calculated as hazard ratios with 95% confidence intervals. Adjustments were made for important confounding factors, including history of attempt. The reference group comprised Swedish-born individuals without mental disorders.

Rates for suicide attempt in individuals with a mental disorder were lower in refugees compared with Swedish-born individuals (480 v. 850 per 100 000 person-years, respectively). This pattern was true for most specific disorders: compared with the reference group, among refugees, multivariable-adjusted hazard ratios for suicide attempt ranged from 3.0 (anxiety) to 7.4 (substance misuse), and among Swedish-born individuals, from 4.9 (stress-related disorder) to 9.3 (substance misuse). For schizophrenia, bipolar disorder and personality disorder, estimates for suicide attempt were comparable between refugees and Swedish-born individuals. Similar patterns were seen for suicide.

For most mental disorders, refugees were less likely to be admitted to hospital for suicide attempt or die by suicide compared with Swedish-born individuals. Further research on risk and protective factors for suicide attempt and suicide among refugees with mental disorders is warranted.

None.

It has been hypothesised that refugees have an increased risk of suicide.

To investigate whether risk of suicide is higher among refugees compared with non-refugee migrants from the same areas of origin and with the Swedish-born population, and to examine whether suicide rates among migrants converge to the Swedish-born population over time.

A population-based cohort design using linked national registers to follow 1 457 898 people born between 1 January 1970 and 31 December 1984, classified by migrant status as refugees, non-refugee migrants or Swedish-born. Participants were followed from their 16th birthday or date of arrival in Sweden until death, emigration or 31 December 2015, whichever came first. Cox regression models estimated adjusted hazard ratios for suicide by migrant status, controlling for age, gender, region of origin and income.

There were no significant differences in suicide risk between refugee and non-refugee migrants (hazard ratio 1.28, 95% CI 0.93–1.76) and both groups had a lower risk of suicide than Swedish born. During their first 5 years in Sweden no migrants died by suicide; however, after 21–31 years their suicide risk was equivalent to the Swedish-born population (hazard ratio 0.94, 95% CI 0.79–1.22). After adjustment for income this risk was significantly lower for migrants than the Swedish-born population.

Being a refugee was not an additional risk factor for suicide. Our findings regarding temporal changes in suicide risk suggest that acculturation and socioeconomic deprivation may account for a convergence of suicide risk between migrants and the host population over time.

None.

Awareness materials featuring ways of coping with suicidal ideation can reduce suicidal ideation, the so-called Papageno effect. All of the previous experimental studies on this subject have been conducted with individuals not at risk of suicide.

To assess effects of suicide awareness materials in a sample of individuals with recent suicidal ideation. Trial registration: German Clinical Trial Registry ID number DRKS00013613.

Adults (n = 266) with recent self-reported suicidal ideation or attempt were randomised to read an educative article featuring a lay individual with personal experience of suicidality (n = 86), a similar article featuring a mental health expert (n = 90), or an unrelated article (n = 90) in a double-blind online randomised controlled trial. Questionnaire data were collected before (T1) and immediately after exposure (T2) as well as 1 week later (study end-point, T3) and analysed with linear mixed models. The primary outcome was suicide risk as assessed using the Survival and Coping Beliefs subscale of the Reasons for Living Inventory (RFLI); secondary outcomes were suicide-prevention knowledge and mood.

There was an immediate beneficial effect on suicide risk in the intervention group exposed to the message delivered by the individual with personal experience (group 1) as compared with the control group that was maintained until the study end-point (study end-point: RFLI score mean difference from baseline within group 1 MD = −0.36 (95% CI −0.66 to −0.06), mean difference compared with control group MD = −0.71 (95% CI −1.27 to −0.14); d = −0.18). The effect was particularly pronounced for individuals with recent suicide attempt (RFLI score at T3, compared with control group: MD = −1.55 (95% CI −2.52 to −0.57); d = −0.23). Participants in this group also showed increased prevention-related knowledge compared with the control group.

Individuals with a recent suicide attempt appear to benefit from a printed narrative of positive coping with suicidal ideation. The intervention materials do not increase short-term suicide risk.

Previous literature has demonstrated a strong association between cigarette smoking, suicidal ideation and suicide attempts. This association has not previously been examined in a causal inference framework and could have important implications for suicide prevention strategies.

We aimed to examine the evidence for an association between smoking behaviours (initiation, smoking status, heaviness, lifetime smoking) and suicidal thoughts or attempts by triangulating across observational and Mendelian randomisation analyses.

First, in the UK Biobank, we calculated observed associations between smoking behaviours and suicidal thoughts or attempts. Second, we used Mendelian randomisation to explore the relationship between smoking and suicide attempts and ideation, using genetic variants as instruments to reduce bias from residual confounding and reverse causation.

Our observational analysis showed a relationship between smoking behaviour, suicidal ideation and attempts, particularly between smoking initiation and suicide attempts (odds ratio, 2.07; 95% CI 1.91–2.26; P < 0.001). The Mendelian randomisation analysis and single-nucleotide polymorphism analysis, however, did not support this (odds ratio for lifetime smoking on suicidal ideation, 0.050; 95% CI −0.027 to 0.127; odds ratio on suicide attempts, 0.053; 95% CI, −0.003 to 0.110). Despite past literature showing a positive dose-response relationship, our results showed no clear evidence for a causal effect of smoking on suicidal ideation or attempts.

This was the first Mendelian randomisation study to explore the effect of smoking on suicidal ideation and attempts. Our results suggest that, despite observed associations, there is no clear evidence for a causal effect.

Alcohol use disorder (AUD) is common and associated with increased risk of suicide.

To examine healthcare utilisation prior to suicide in persons with AUD in a large population-based cohort, which may reveal opportunities for prevention.

A national cohort study was conducted of 6 947 191 adults in Sweden in 2002, including 256 647 (3.7%) with AUD, with follow-up for suicide through 2015. A nested case–control design examined healthcare utilisation among people with AUD who died by suicide and 10:1 age- and gender-matched controls.

In 86.7 million person-years of follow-up, 15 662 (0.2%) persons died by suicide, including 2601 (1.0%) with AUD. Unadjusted and adjusted relative risks for suicide associated with AUD were 8.15 (95% CI 7.86–8.46) and 2.22 (95% CI 2.11–2.34). Of the people with AUD who died by suicide, 39.7% and 75.6% had a healthcare encounter <2 weeks or <3 months before the index date respectively, compared with 6.3% and 25.4% of controls (adjusted prevalence ratio (PR) and difference (PD), <2 weeks: PR = 3.86, 95% CI 3.50–4.25, PD = 26.4, 95% CI 24.2–28.6; <3 months: PR = 2.03, 95% CI 1.94–2.12, PD = 34.9, 95% CI 32.6–37.1). AUD accounted for more healthcare encounters within 2 weeks of suicide among men than women (P = 0.01). Of last encounters, 48.1% were in primary care and 28.9% were in specialty out-patient clinics, mostly for non-psychiatric diagnoses.

Suicide among persons with AUD is often shortly preceded by healthcare encounters in primary care or specialty out-patient clinics. Encounters in these settings are important opportunities to identify active suicidality and intervene accordingly in patients with AUD.

Longitudinal studies of patterns of healthcare contacts in those who die by suicide to identify those at risk are scarce.

To examine type and timing of healthcare contacts in those who die by suicide.

A population-based electronic case–control study of all who died by suicide in Wales, 2001–2017, linking individuals’ electronic healthcare records from general practices, emergency departments and hospitals. We used conditional logistic regression to calculate odds ratios, adjusted for deprivation. We performed a retrospective continuous longitudinal analysis comparing cases’ and controls’ contacts with health services.

We matched 5130 cases with 25 650 controls (5 per case). A representative cohort of 1721 cases (8605 controls) were eligible for the fully linked analysis. In the week before their death, 31.4% of cases and 15.6% of controls contacted health services. The last point of contact was most commonly associated with mental health and most often occurred in general practices. In the month before their death, 16.6 and 13.0% of cases had an emergency department contact and a hospital admission respectively, compared with 5.5 and 4.2% of controls. At any week in the year before their death, cases were more likely to contact healthcare services than controls. Self-harm, mental health and substance misuse contacts were strongly linked with suicide risk, more so when they occurred in emergency departments or as emergency admissions.

Help-seeking occurs in those at risk of suicide and escalates in the weeks before their death. There is an opportunity to identify and intervene through these contacts.