Socioeconomic factors outweigh climate in the regional difference of suicide death rate in Taiwan

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.

Increase in Search Interest for "Suicide" and "Depression" for Particular Days of the Week and Times of Day: Analysis Based on Google Trends

Depression is the most common disorder in people who attempt suicide or die by suicide. Research review indicate that therapy of depression (including psychoeducation) is one of the main factors in the prevention of suicidal behavior. In this paper we examine the intensification of search interest for the terms "depression" and "suicide" in Google search engine with regard to the time of day and day of the week in Poland, Germany, Great Britain and Italy. The goal of the study was to determine if there are any days of the week or hours when search for "suicide" and "depression" particularly increases. Numerous studies focusing not only on the seasonality of suicidal behavior, but also on the days of the week and hours, indicate that it is most often undertaken on Mondays in the night and early morning hours. The results of the research being the basis of this paper show a certain time coincidence: first, the increase in search interest for "suicide" and "depression" and then undertaking suicidal behavior (suicide and suicide attempts). Searching for terms "suicide" and "depression" usually took place (except in Italy) at weekends and most often in the late evening hours and at night. The conclusions from the research can be used in suicide prevention activities, for example in determining the hours of operation of individual helpline numbers.

The impact of daylight on suicide rates

Since Durkheim and Morselli found a spring peak in suicides in the late 19th century, researchers have presented possible explanations, including daylight variation, for this seasonal pattern. Our identification strategy exploits the idiosyncratic variation in daylight within Norwegian regions, arising from the country's substantial latitudinal range. We use full population data for a period of 45 years in a pre-registered research design. We find a small and non-significant relationship: One extra hour of daylight increases the suicide rate by merely 0.75 % (95 % CI: -0.4 % to 1.9 %).

Climate rather than economic variables might have caused increase in US homicide but not suicide rates during the Great Depression

BACKGROUND

It is widely believed that during the Great Depression (1929-1933) there was a rise in suicidal rates which was causally related to the increase in unemployment. There are no studies on the effect the Great Depression had on homicidal rates METHODS: The data concerning suicide, homicide, economic and climatic variables for the years 1900-1940 for the whole of the US were gathered from the US Center for Disease Control, the Maddison Project, the National Bureau of Economic Research and the National Climatic Data Center. Time Series Analysis was performed.

RESULTS

The results are inconclusive on the role of economic factors but preclude any role of climate on suicidal rates during the years 1900-1940 in the US. Suicidal rates might have a 24-years periodicity, however much longer time series are needed to confirm this. On the contrary they strongly suggest an effect of higher temperatures on homicidal rates after 1922.

CONCLUSIONS

The results of the current study suggest a direct and clear effect of climate (higher temperatures) on the increasing homicidal rates in the US after 1922 but failed to establish a causal relationship between suicide rates and economic or climate variables. These should be considered together with increasing concerns on the possible effect of climate change on mental health.

Association between daily ambient temperature and drug overdose in Tokyo: a time-series study

BACKGROUND

Previous studies have reported that high ambient temperature is associated with increased risk of suicide; however, the association has not been extensively investigated with drug overdose which is the most common method of unsuccessful suicidal behavior in Japan. Therefore, this study aims to examine the short-term association between daily mean temperature and the incidence of self-harm attempts by drug overdose in Tokyo, Japan.

METHODS

We collected the emergency ambulance dispatch data and daily meteorological data in Tokyo from 2010 to 2014. A quasi-Poisson regression model incorporating a distributed lag non-linear function was applied to estimate the non-linear and delayed association between temperature and drug overdose, adjusting for relative humidity, seasonal and long-term trends, and days of the week. Sex, age and location-specific associations of ambient temperature with drug overdose was also estimated.

RESULTS

12,937 drug overdose cases were recorded during the study period, 73.9% of which were female. We observed a non-linear association between temperature and drug overdose, with the highest risk observed at 21 °C. The highest relative risk (RR) was 1.30 (95% Confidence Interval (CI): 1.10-1.67) compared with the risk at the first percentile of daily mean temperature (2.9 °C) over 0-4 days lag period. In subgroup analyses, the RR of a drug overdose at 21 °C was 1.36 (95% CI: 1.02-1.81) for females and 1.07 (95% CI: 0.66-1.75) for males. Also, we observed that the risk was highest among those aged ≥65 years (RR = 2.54; 95% CI: 0.94-6.90), followed by those aged 15-34 years (RR = 1.25; 95% CI: 0.89-1.77) and those aged 35-64 years (RR = 1.15; 95% CI: 0.78-1.68). There was no evidence for the difference in RRs between urban (23 special wards) and sub-urban areas in Tokyo.

CONCLUSIONS

An increase in daily mean temperature was associated with increased drug overdose risk. This study indicated the positive non-linear association between temperature and incomplete attempts by drug overdose. The findings of this study may add further evidence of the association of temperature on suicidal behavior and suggests increasing more research and investigation of other modifying factors.

Socioeconomic disparities in suicide: Causation or confounding?

BACKGROUND

Despite an overall reduction in suicide, educational disparities in suicide have not decreased over the last decade. The mechanisms behind educational disparities in suicide, however, remain unclear: low educational status may increase the risk of suicide ("causation") or low educational status and suicide may share confounders. This paper assesses whether educational disparities in suicide (EDS) are more likely to be due to causation.

METHOD

The DEMETRIQ study collected and harmonized register-based data on mortality follow-up from forty population censuses from twelve European populations. More than 102,000 suicides were registered over 392 million person-years. Three analyses were carried out. First, we applied an instrumental variable approach that exploits changes in the legislation on compulsory educational age to instrument educational status. Second, we analyzed EDS by age under the hypothesis that increasing EDS over the life cycle supports causation. Finally, we compared EDS in men and women under the assumption that greater EDS in women would support causation.

FINDINGS

The instrumental variable analysis showed no evidence for causation between higher education and suicide, for men or women. The life-cycle analysis showed that the decrease of educational inequalities in suicide between the baseline 1991 period and the 2001 follow-up period was more pronounced and statistically significant in the first three younger age groups. The gender analysis indicated that EDS were systematic and greater in men than in women: the rate ratio of suicide for men with low level of education (RR = 2.51; 95%CI:2.44-2.58) was higher than the rate ratio in women (RR = 1.32; 95CI%:1.26-1.38).

INTERPRETATION

Overall, there was little support for the causation hypothesis, suggesting that the association between education and suicide is confounded. Educational inequalities in suicide should be addressed in early life by early targeting of groups who struggle to complete their education and display higher risk of mental disorder or of mental health vulnerabilities.

Association between lithium in tap water and suicide mortality rates in Miyazaki Prefecture

Background

Most studies have reported that suicide mortality rates are negatively associated with lithium levels in tap water; however, a few studies showed either no association or a positive association. Thus, the association between suicide mortality and lithium levels in tap water remains controversial. To clarify the association, our study evaluated the association between lithium levels in tap water and suicide mortality rates in Miyazaki Prefecture of Japan, after adjusting for confounding factors.

Methods

We measured lithium levels in tap water across the 26 municipalities of Miyazaki Prefecture in Japan. We examined the standardized mortality ratio (SMR) for suicide in each municipality and used the data as the average suicide SMRs over 5 years (2009–2013). Weighted least-squares regression analysis, adjusted for the size of each municipality’s population, was used to investigate the association between lithium levels in tap water and suicide SMRs. In addition to a crude model, in an adjusted model, potential confounding factors (proportion of elderly people, proportion of one-person households, annual marriage rate, annual mean income, unemployment rate, the density of medical doctors per 100,000 people, annual total rainfall, and proportion of people with a college education or higher) were added as covariates.

Results

We showed that male and female suicide SMRs were not associated with lithium levels in tap water in Miyazaki Prefecture. After adjusting for confounders, male suicide SMRs were significantly and positively associated with the proportion of elderly people in the population and annual total rainfall, and female suicide SMRs were associated with the proportion of elderly people in the population.

Conclusions

No association between lithium levels in tap water and suicide mortality rates was found in Miyazaki Prefecture.

Temperature and mental health: Evidence from the spectrum of mental health outcomes

This paper characterizes the link between ambient temperatures and a broad set of mental health outcomes. We find that higher temperatures increase emergency department visits for mental illness, suicides, and self-reported days of poor mental health. Specifically, cold temperatures reduce negative mental health outcomes while hot temperatures increase them. Our estimates reveal no evidence of adaptation, instead the temperature relationship is stable across time, baseline climate, air conditioning penetration rates, accessibility of mental health services, and other factors. The character of the results suggests that temperature affects mental health very differently than physical health, and more similarly to other psychological and behavioral outcomes. We provide suggestive evidence for sleep disruption as an active mechanism behind our results and discuss the implications of our findings for the allocation of mental health services and in light of climate change.

Ambient temperature, sunlight duration, and suicide: A systematic review and meta-analysis

BACKGROUND

The relationship between sunlight hours, temperature, and suicide has been investigated in many previous studies, but with inconsistent findings. We conducted this meta-analysis aiming at providing clear evidence about whether sunlight hours and temperature can affect the risk of suicide.

METHODS

Relevant literature published before 7 Jul 2018 was searched in three electronic database of PubMed, Web of science and Cochrane. Between-study heterogeneity in the effect estimates were examined by study design (i.e., exposure time resolution, temperature measure and suicide classification) and population vulnerability (i.e., sex, national income level, climate zone and study location).

RESULTS

Regarding temperature-suicide association, we identified 14 studies that provided 23 effect estimates for meta-analysis. Our random-effects model showed that each 1 °C increase in temperature was significantly associated with a 1% increase in the incidence of suicide (Incidence Rate Radio (IRR) = 1.01; 95%CI = 1.00-1.02; p < 0.05). As for sunlight duration and suicide, 11 effect estimates from 4 studies were pooled using a fixed-effects model. Significant association between sunlight duration (per 1 h increase) and the risk of suicide was not observed, and the pooled IRR was 1.00 (95%CI = 0.99-1.01; p > 0.05). There was significant heterogeneity between previous studies' effect estimates, and significantly lower heterogeneity was noted for the female group, for studies that did analyses at daily scale, and for studies using mean temperature as the exposure indicator.

CONCLUSION

Our findings suggest a significant and positive association between temperature rises and incidence of suicide, and a non-significant association between sunlight duration and incidence of suicide. Populations living in tropical and temperate zones or at middle-income level may be particularly vulnerable to temperature increase.

Weather and Suicide: A Decade Analysis in the Five Largest Capital Cities of Colombia

Historically, seasonal variations in suicide rates were thought to be associated with changes in weather. Most of this evidence however, is based on studies that were conducted in developed countries that are located outside the tropics. As such, it is necessary to examine this association in developing countries, such as Colombia, which do not experience marked seasons. In addition, it is important to adjust for the effect of holidays when analyzing this association as they have been reported to be a relevant confounding factor. Our objective was to estimate the association between daily suicide incidence among men and women in five major Colombian cities (Bogotá, Medellin, Cali, Barranquilla, and Bucaramanga) and daily temperature and rainfall. For this purpose, we conducted a multi-city, multi-temporal ecological study from 2005 to 2015, using data from the suicide mortality registries (provided by the National Administrative Department of Statistics). Daily measurements of the two weather variables were obtained from the official historical registry of the meteorological station at each city airport. We used these data to estimate conditional Poisson models for daily suicide counts, stratifying by sex and adjusting for holidays. Although we found that none of the weather variable estimators could reject the null hypothesis, we uncovered an association between suicide incidence and long weekends in the total suicide model (Incidence Rate Ratio (IRR): 1.19, 95% confidence interval (CI): 1.04⁻1.23). We found no evidence of association between weather variables and suicide in Colombia. Our study is based on daily observations and it provides evidence of absence of this association in a tropical country that does not experience marked seasons.

Where are weather-suicide associations valid? An examination of nine US counties with varying seasonality

There has been much research on the associations between weather variables and suicide rates. However, the state of understanding has remained rather stagnant due to many contradictory findings. The purpose of this project is to examine a larger database of suicides that includes a longer and more recent period of record (1975-2010) across numerous locations in the USA. In all, we examine nine total counties (and the primary city associated with them) with a special effort made to compare locations with varying degrees of temperature seasonality: Cook (Chicago), Fulton (Atlanta), King (Seattle), Los Angeles (Los Angeles), Maricopa (Phoenix), Miami-Dade (Miami), Philadelphia (Philadelphia), Salt Lake (Salt Lake City), and St. Louis (St. Louis). We first examine the unique seasonal cycle in suicides evident in each locale and then use distributed lag nonlinear modeling (DLNM) to relate the suicide data to daily surface temperatures. Results suggest that a late spring/summer peak generally exists in suicide rates, and above average temperatures are associated with increased suicide risk in almost all study counties. Further, it appears that these associations can be found in both mid-latitude and sub-tropical climate types.

The effect of altitude and climate on the suicide rates in Turkey

Suicide is one of the most important public health problems. There was an association between suicide and several factors such as psychiatric diseases and psychological characteristics, somatic illness, cultural, socioeconomic, familial, occupational and individual risk factors. Also, high altitude and climatic factors including high temperature, cloudiness, more sunshine and low rainfalls were defined as some of these risk factors in the literature. In this study, we aimed to investigate correlation between suicide rates and altitudes of all cities in Turkey and between suicide rates and climatic factors including Rainfall Activity Index, Winter Mean Temperatures, Summer Mean Temperatures and Temperature Difference between January and July previously defined by several authors in the broad series in Turkey. In Turkey, 29865 suicidal deaths occurred in 10 years period between 2006 and 2015. Of them, 21020 (70.4%) were males and 8845 (29.6%) were females. In this study, we found that high altitude above 1500 m, winter median temperature lower than -10 °C and hard temperature changes above 25 °C between winter and summer of settlements were important factors that affected on female suicide rates appropriate to knowledge which defined in previous studies. In conclusion, we suggested that the associations among suicide rates with altitudes and climate should be studied in wider series obtained from different countries for reaching more reliable results.

Lithium levels in the public drinking water supply and risk of suicide: A pilot study

Suicide is a major public health concern affecting both the society and family life. There are data indicating that higher level lithium intake with drinking water is associated with lower suicide rate. This pilot study examined the relationship between lithium levels in drinking water and suicide rates in Lithuania. Twenty-two samples from public drinking water systems were taken in 9 cities of Lithuania. The lithium concentration in these samples was determined by inductively coupled plasma mass spectrometry (ICP-MS). The suicide data were obtained from the Lithuania Database of Health Indicators, and comprised all registered suicides across all ages and gender within the 5-year period from 2009 to 2013. The study demonstrated an inverse correlation between levels of lithium (log natural transformed), number of women for 1000 men and standardized mortality rate for suicide among total study population. After adjusting for confounder (the number of women for 1000 men), the lithium level remained statistically significant in men, but not in women. Our study suggested that higher levels of lithium in public drinking water are associated with lower suicide rates in men. It might have a protective effect on the risk of suicide in men.

Climate change but not unemployment explains the changing suicidality in Thessaloniki Greece (2000-2012)

INTRODUCTION

Recently there was a debate concerning the etiology behind attempts and completed suicides. The aim of the current study was to search for possible correlations between the rates of attempted and completed suicide and climate variables and regional unemployment per year in the county of Thessaloniki, Macedonia, northern Greece, for the years 2000-12.

MATERIAL AND METHODS

The regional rates of suicide and attempted suicide as well as regional unemployment were available from previous publications of the authors. The climate variables were calculated from the daily E-OBS gridded dataset which is based on observational data

RESULTS

Only the male suicide rates correlate significantly with high mean annual temperature but not with unemployment. The multiple linear regression analysis results suggest that temperature is the only variable that determines male suicides and explains 51% of their variance. Unemployment fails to contribute significantly to the model. There seems to be a seasonal distribution for attempts with mean rates being higher for the period from May to October and the rates clearly correlate with temperature. The highest mean rates were observed during May and August and the lowest during December and February. Multiple linear regression analysis suggests that temperature also determines the female attempts rate although the explained variable is significant but very low (3-5%)

CONCLUSION

Climate variables and specifically high temperature correlate both with suicide and attempted suicide rates but with a different way between males and females. The climate effect was stronger than the effect of unemployment.

Suicide and Ambient Temperature in East Asian Countries: A Time-Stratified Case-Crossover Analysis

BACKGROUND

A limited number of studies suggest that ambient temperature contributes to suicide; these studies typically focus on a single nation and use temporally and spatially aggregated data.

OBJECTIVE

We evaluated the association between ambient temperature and suicide in multiple cities in three East Asian countries.

METHODS

A time-stratified case-crossover method was used to explore the relationship between temperature and suicide, adjusting for potential time-varying confounders and time-invariant individual characteristics. Sex- and age-specific associations of temperature with suicide were estimated, as were interactions between temperature and these variables. A random-effects meta-analysis was used to estimate country-specific pooled associations of temperature with suicide.

RESULTS

An increase in temperature corresponding to half of the city-specific standard deviation was positively associated with suicide in most cities, although average suicide rates varied substantially. Pooled country-level effect estimates were 7.8% (95% CI: 5.0, 10.8%) for a 2.3°C increase in ambient temperature in Taiwan, 6.8% (95% CI: 5.4, 8.2%) for a 4.7°C increase in Korea, and 4.5% (95% CI: 3.3, 5.7%) for a 4.2°C increase in Japan. The association between temperature and suicide was significant even after adjusting for sunshine duration; the association between sunshine and suicide was not significant. The associations were greater among men than women in 12 of the 15 cities although not significantly so. There was little evidence of a consistent pattern of associations with age. In general, associations were strongest with temperature on the same day or the previous day, with little evidence of associations with temperature over longer lags (up to 5 days).

CONCLUSIONS

We estimated consistent positive associations between suicide and elevated ambient temperature in three East Asian countries, regardless of country, sex, and age.

CITATION

Kim Y, Kim H, Honda Y, Guo YL, Chen BY, Woo JM, Ebi KL. 2016. Suicide and ambient temperature in East Asian countries: a time-stratified case-crossover analysis. Environ Health Perspect 124:75-80; http://dx.doi.org/10.1289/ehp.1409392.

Relationship of suicide rates with climate and economic variables in Europe during 2000-2012

BACKGROUND

It is well known that suicidal rates vary considerably among European countries and the reasons for this are unknown, although several theories have been proposed. The effect of economic variables has been extensively studied but not that of climate.

METHODS

Data from 29 European countries covering the years 2000-2012 and concerning male and female standardized suicidal rates (according to WHO), economic variables (according World Bank) and climate variables were gathered. The statistical analysis included cluster and principal component analysis and categorical regression.

RESULTS

The derived models explained 62.4 % of the variability of male suicidal rates. Economic variables alone explained 26.9 % and climate variables 37.6 %. For females, the respective figures were 41.7, 11.5 and 28.1 %. Male suicides correlated with high unemployment rate in the frame of high growth rate and high inflation and low GDP per capita, while female suicides correlated negatively with inflation. Both male and female suicides correlated with low temperature.

DISCUSSION

The current study reports that the climatic effect (cold climate) is stronger than the economic one, but both are present. It seems that in Europe suicidality follows the climate/temperature cline which interestingly is not from south to north but from south to north-east. This raises concerns that climate change could lead to an increase in suicide rates. The current study is essentially the first successful attempt to explain the differences across countries in Europe; however, it is an observational analysis based on aggregate data and thus there is a lack of control for confounders.

Trace lithium is inversely associated with male suicide after adjustment of climatic factors

BACKGROUND

Previously, we showed the inverse association between lithium in drinking water and male suicide in Kyushu Island. The narrow variation in meteorological factors of Kyushu Island and a considerable amount of evidence regarding the role of the factors on suicide provoked the necessities of adjusting the association by the wide variation in sunshine, temperature, rain fall, and snow fall.

METHODS

To keep the wide variation in meteorological factors, we combined the data of Kyushu (the southernmost city is Itoman, 26°) and Hokkaido (the northernmost city is Wakkanai, 45°). Multiple regression analyses were used to predict suicide SMRs (total, male and female) by lithium levels in drinking water and meteorological factors.

RESULTS

After adjustment of meteorological factors, lithium levels were significantly and inversely associated with male suicide SMRs, but not with total or female suicide SMRs, across the 153 cities of Hokkaido and Kyushu Islands. Moreover, annual total sunshine and annual mean temperature were significantly and inversely associated with male suicide SMRs whereas annual total rainfall was significantly and directly associated with male suicide SMRs.

LIMITATIONS

The limitations of the present study include the lack of data relevant to lithium levels in food and the proportion of the population who drank tap water and their consumption habits.

CONCLUSIONS

The present findings suggest that trace lithium is inversely associated with male but not female suicide after adjustment of meteorological factors.

Associations between climate variability, unemployment and suicide in Australia: a multicity study

BACKGROUND

A number of studies have examined the associations of suicide with meteorological variables (MVs) and socioeconomic status but the results are inconsistent. This study assessed whether MVs and unemployment were associated with suicide in eight Australian capital cities.

METHODS

Data on suicide, population and unemployment rate (UER) between 1985 and 2005 were from the Australian Bureau of Statistics. MVs was provided by Australian Bureau of Meteorology. A generalized linear regression model with Poisson link was applied to explore the association of suicide with MVs and UER.

RESULTS

Temperature difference (ΔT, the difference in mean temperature between current month and previous one month) was positively associated with suicide in Sydney, Melbourne, Brisbane and Hobart. There was also a significant and positive association between UER and suicide in Sydney, Melbourne, Brisbane and Perth. MVs had more significant associations with violent suicide than that of non-violent suicide. There were no consistent associations between other MVs and suicide. A significant interaction between ΔT and UER on suicide was found in Sydney, Melbourne and Brisbane, such that increased temperature amplified the magnitude of the association between UER and suicide.

CONCLUSIONS

ΔT and UER appeared to jointly influence the occurrence of suicide in Australian capital cities. This finding may have implications for developing effective suicide prevention strategies.

Environmental correlates of mental health measures for women in Western Australia

A recent study in Western Australia identified area level associations between soil salinisation and hospital admissions for depression. Our study assessed the quantitative relationship between mental health measures at the individual level and location specific environmental measurements on salinity, as well as two other indicators of environmental degradation and change: land surface temperature and normalised difference vegetation index, a proxy for rainfall. Location-specific environmental measurements were linked to individual mental health scores of women in three age cohorts from the Australian Longitudinal Study on Women's Health using a geographic information system. Bayesian geostatistical linear regression models were developed to assess associations between environmental exposures and mental health scores of women. In contrast to previous studies using area level measures, our study found no associations between individual level measurements of mental health scores for women in south-west Western Australia and salinity, LST or NDVI.

Association of weekly suicide rates with temperature anomalies in two different climate types

Annual suicide deaths outnumber the total deaths from homicide and war combined. Suicide is a complex behavioral endpoint, and a simple cause-and-effect model seems highly unlikely, but relationships with weather could yield important insight into the biopsychosocial mechanisms involved in suicide deaths. This study has been designed to test for a relationship between air temperature and suicide frequency that is consistent enough to offer some predictive abilities. Weekly suicide death totals and anomalies from Toronto, Ontario, Canada (1986-2009) and Jackson, Mississippi, USA (1980-2006) are analyzed for relationships by using temperature anomaly data and a distributed lag nonlinear model. For both analysis methods, anomalously cool weeks show low probabilities of experiencing high-end suicide totals while warmer weeks are more likely to experience high-end suicide totals. This result is consistent for Toronto and Jackson. Weekly suicide totals demonstrate a sufficient association with temperature anomalies to allow some prediction of weeks with or without increased suicide frequency. While this finding alone is unlikely to have immediate clinical implications, these results are an important step toward clarifying the biopsychosocial mechanisms of suicidal behavior through a more nuanced understanding of the relationship between temperature and suicide.

Attribution of mental disorders in suicide occurrence

The present study aimed to determine attribution of mental disorders in suicide occurrence. By a cross-sectional study, all suicide records (n = 5188), between 1993 and 2009 in Ilam province, were investigated. Multiple logistic regression analysis was adopted. Totally, 27.5% of the suicides occurred due to mental disorders. This was significantly higher in males (29.3%), individuals born in 1996 (44%) and 1990s (30.3%), those aged 30 years and above (33.2%) and suicide attempters (28.3%), respectively and separately. The risk of suicide due to mental disorders was observed for females (OR = 0.85, CI = 0.74-0.97), those born in 1994 (OR = 2.82, CI = 1.27-6.24), completed suicides (OR = 0.81, CI = 0.68-0.97) and the age group 25 to 29 years old (OR = 0.82, CI = 0.66-1.01). Suicide due to mental disorders was higher among males compared to females, the rate of which was directly proportional to attempted suicide and age. It is therefore recommended that health educations be seriously carried on targeted groups.

Socio-environmental drivers and suicide in Australia: Bayesian spatial analysis

BACKGROUND

The impact of socio-environmental factors on suicide has been examined in many studies. Few of them, however, have explored these associations from a spatial perspective, especially in assessing the association between meteorological factors and suicide. This study examined the association of meteorological and socio-demographic factors with suicide across small areas over different time periods.

METHODS

Suicide, population and socio-demographic data (e.g., population of Aboriginal and Torres Strait Islanders (ATSI), and unemployment rate (UNE) at the Local Government Area (LGA) level were obtained from the Australian Bureau of Statistics for the period of 1986 to 2005. Information on meteorological factors (rainfall, temperature and humidity) was supplied by Australian Bureau of Meteorology. A Bayesian Conditional Autoregressive (CAR) Model was applied to explore the association of socio-demographic and meteorological factors with suicide across LGAs.

RESULTS

In Model I (socio-demographic factors), proportion of ATSI and UNE were positively associated with suicide from 1996 to 2000 (Relative Risk (RR)ATSI = 1.0107, 95% Credible Interval (CI): 1.0062-1.0151; RRUNE = 1.0187, 95% CI: 1.0060-1.0315), and from 2001 to 2005 (RRATSI = 1.0126, 95% CI: 1.0076-1.0176; RRUNE = 1.0198, 95% CI: 1.0041-1.0354). Socio-Economic Index for Area (SEIFA) and IND, however, had negative associations with suicide between 1986 and 1990 (RRSEIFA = 0.9983, 95% CI: 0.9971-0.9995; RRATSI = 0.9914, 95% CI: 0.9848-0.9980). Model II (meteorological factors): a 1°C higher yearly mean temperature across LGAs increased the suicide rate by an average by 2.27% (95% CI: 0.73%, 3.82%) in 1996-2000, and 3.24% (95% CI: 1.26%, 5.21%) in 2001-2005. The associations between socio-demographic factors and suicide in Model III (socio-demographic and meteorological factors) were similar to those in Model I; but, there is no substantive association between climate and suicide in Model III.

CONCLUSIONS

Proportion of Aboriginal and Torres Strait Islanders, unemployment and temperature appeared to be statistically associated with of suicide incidence across LGAs among all selected variables, especially in recent years. The results indicated that socio-demographic factors played more important roles than meteorological factors in the spatial pattern of suicide incidence.

Filicide-suicide ideation among Taiwanese parents with school-aged children: prevalence and associated factors

This study explored the prevalence of filicide-suicide ideation among Taiwanese parents with school-aged children. Multiple risk factors associated with filicide-suicide ideation were assessed, and the potential effect of traditional family values was evaluated. A random sample of 1,564 parents was recruited from 21 elementary schools in a rural area of Taiwan. Potential risk factors, including demographics, family finance, psychological maladjustment, family interaction, and cultural beliefs, were further examined using a hierarchical logistic regression. Overall, 14.6% of the respondents reported having filicide-suicide ideation during the past year. The hierarchical logistic regression analysis showed that demographic factors including age, gender, and ethnicity had no significant effect. Family finances, depression, and conflict with the respondent's spouse were positively associated with filicide-suicide ideation. Finally, the parents' beliefs in traditional family values had a positive effect on filicide-suicide ideation. In other words, filicide-suicide thoughts were more common among those who upheld a strong parental responsibility for care giving and family solidarity. This study revealed a substantial prevalence of filicide-suicide ideation among local parents and identified a number of risk factors associated with those thoughts, namely family financial status, parental depression, and conflict with one's spouse. More importantly, the results highlighted the effect of traditional family values in the process. The potential intention of filicide-suicide as mercy killing and its cultural relevance were discussed.

The impact of heat on mortality and morbidity in the Greater Metropolitan Sydney Region: a case crossover analysis

BACKGROUND

This study examined the association between unusually high temperature and daily mortality (1997-2007) and hospital admissions (1997-2010) in the Sydney Greater Metropolitan Region (GMR) to assist in the development of targeted health programs designed to minimise the public health impact of extreme heat.

METHODS

Sydney GMR was categorized into five climate zones. Heat-events were defined as severe or extreme. Using a time-stratified case-crossover design with a conditional logistic regression model we adjusted for influenza epidemics, public holidays, and climate zone. Odds ratios (OR) and 95% confidence intervals were estimated for associations between daily mortality and hospital admissions with heat-event days compared to non-heat event days for single and three day heat-events.

RESULTS

All-cause mortality overall had similar magnitude associations with single day and three day extreme and severe events as did all cardiovascular mortality. Respiratory mortality was associated with single day and three day severe events (95th percentile, lag0: OR = 1.14; 95%CI: 1.04 to 1.24). Diabetes mortality had similar magnitude associations with single day and three day severe events (95th percentile, lag0: OR = 1.22; 95%CI: 1.03 to 1.46) but was not associated with extreme events. Hospital admissions for heat related injuries, dehydration, and other fluid disorders were associated with single day and three day extreme and severe events. Contrary to our findings for mortality, we found inconsistent and sometimes inverse associations for extreme and severe events with cardiovascular disease and respiratory disease hospital admissions. Controlling for air pollutants did not influence the mortality associations but reduced the magnitude of the associations with hospital admissions particularly for ozone and respiratory disease.

CONCLUSIONS

Single and three day events of unusually high temperatures in Sydney are associated with similar magnitude increases in mortality and hospital admissions. The trend towards an inverse association between cardio-vascular admissions and heat-events and the strong positive association between cardio-vascular mortality and heat-events suggests these events may lead to a rapid deterioration in persons with existing cardio-vascular disease resulting in death. To reduce the adverse effects of high temperatures over multiple days, and less extreme but more frequent temperatures over single days, targeted public health messages are critical.

Risk factors for suicide in Japan: a model of predicting suicide in 2008 by risk factors of 2007

BACKGROUND

This study aims to comprehensively investigate the causal relationship between suicide and its risk factors in a longitudinal design.

METHODS

A model was derived in which suicide rate in 2008 was longitudinally and comprehensively predicted by potential risk factors recorded one year before (2007) which included personal and interpersonal factors, medical factors, economic factors, climate factors, alcoholic factors, and ω-3 fatty-acid factors.

RESULTS

In males, elderly population rate and complete unemployment rate predicted SMR of suicide significantly and positively whereas marriage rate and annual postal savings per person predicted SMR of suicide significantly and negatively. Also in females, complete unemployment rate predicted SMR of suicide significantly and positively whereas annual mean temperature predicted SMR of suicide significantly and negatively.

LIMITATIONS

The limitations of this study are that predictions are based on the data of only the recent two years, that these epidemiological data cannot be always extrapolated to individuals, and that other factors should be taken into consideration to female suicide.

CONCLUSIONS

The present findings suggest that male suicide may be accounted for by older age, more complete employment rate, less marriage rate and less annual postal savings whereas female suicide may be accounted for by more complete employment rate and lower annual mean temperature.

Temperature-associated suicide mortality: contrasting roles of climatic warming and the suicide prevention program in Finland

OBJECTIVES

Suicide is a notable cause of death worldwide, and while suicidal behavior appears to be associated with variations in temperature, no estimations are available of climate change impacts on suicide rates. The study aims to evaluate the influence of temperature on suicide mortality, especially on multi-decadal and longer time scales, that is, at scales on which the ongoing warming distinctly operates and is correspondingly appropriate for the current policy responses to warming climate.

METHODS

Our results are based on an extraordinarily long record of deaths from suicide in Finland from 1751 to 2008, and a similarly long climatic record of ambient temperatures correlative of environmental change in the study region.

RESULTS

We show that temperature variability explains more than 60 % of the total suicide variance up until the initiation of a national suicide prevention program. Despite ongoing warming, suicide rates have declined since the initiation of the program.

CONCLUSION

By understanding the complexity of suicidal behavior as a response to ambient warming and the observed effects of interventions, our results underline the pressing need for a network of prevention programs to battle against temperature-mediated health hazards.

Atmospheric pressure and suicide attempts in Helsinki, Finland

The influence of weather on mood and mental health is commonly debated. Furthermore, studies concerning weather and suicidal behavior have given inconsistent results. Our aim was to see if daily weather changes associate with the number of suicide attempts in Finland. All suicide attempts treated in the hospitals in Helsinki, Finland, during two separate periods, 8 years apart, were included. Altogether, 3,945 suicide attempts were compared with daily weather parameters and analyzed with a Poisson regression. We found that daily atmospheric pressure correlated statistically significantly with the number of suicide attempts, and for men the correlation was negative. Taking into account the seasonal normal value during the period 1971-2000, daily temperature, global solar radiation and precipitation did not associate with the number of suicide attempts on a statistically significant level in our study. We concluded that daily atmospheric pressure may have an impact on suicidal behavior, especially on suicide attempts of men by violent methods (P < 0.001), and may explain the clustering of suicide attempts. Men seem to be more vulnerable to attempt suicide under low atmospheric pressure and women under high atmospheric pressure. We show only statistical correlations, which leaves the exact mechanisms of interaction between weather and suicidal behavior open. However, suicidal behavior should be assessed from the point of view of weather in addition to psychiatric and social aspects.

Suicide and drought in New South Wales, Australia, 1970-2007

There is concern in Australia that droughts substantially increase the incidence of suicide in rural populations, particularly among male farmers and their families. We investigated this possibility for the state of New South Wales (NSW), Australia between 1970 and 2007, analyzing data on suicides with a previously established climatic drought index. Using a generalized additive model that controlled for season, region, and long-term suicide trends, we found an increased relative risk of suicide of 15% (95% confidence interval, 8%-22%) for rural males aged 30-49 y when the drought index rose from the first quartile to the third quartile. In contrast, the risk of suicide for rural females aged >30 y declined with increased values of the drought index. We also observed an increased risk of suicide in spring and early summer. In addition there was a smaller association during unusually warm months at any time of year. The spring suicide increase is well documented in nontropical locations, although its cause is unknown. The possible increased risk of suicide during drought in rural Australia warrants public health focus and concern, as does the annual, predictable increase seen each spring and early summer. Suicide is a complex phenomenon with many interacting social, environmental, and biological causal factors. The relationship between drought and suicide is best understood using a holistic framework. Climate change projections suggest increased frequency and severity of droughts in NSW, accompanied and exacerbated by rising temperatures. Elucidating the relationships between drought and mental health will help facilitate adaptation to climate change.

Effects of sunshine on suicide rates

OBJECTIVES

Seasonal spring peaks of suicide are well described in epidemiological studies, but their origin is poorly understood. More recent evidence suggests that this peak may be associated with the increase in the duration of sunshine in spring. We investigated the effect of number of sunshine hours per month on suicide rates in Austria between 1996 and 2006.

METHODS

Suicide data, differentiated by month of suicide, sex, and method of suicide (violent vs nonviolent methods), were provided by Statistics Austria. Data on the average number of sunshine hours per month were calculated from 39 representative meteorological stations (provided by the Austrian Central Institute for Meteorology and Geodynamics). For statistical analysis, analysis of variance tests, Kruskal-Wallis tests, and Pearson correlation tests were used.

RESULTS

A total of 16,673 suicides with a median of 126 ± 19.8 suicides per month occurred in the examined period. A clear seasonal pattern was observed, with suicide frequencies being highest between March and May and lowest between November and January (df = 11, F = 5.2, P < .0001) for men (df = 11, F = 4.9, P < .0001) and women (df = 11, F = 2.4, P = .008). The average number of sunshine hours per month was significantly correlated with the number of suicides among both sexes (r = .43, P < .0001), violent methods (r = .48, P < .0001) but not with nonviolent methods (r = .03, P = .707).

CONCLUSIONS

This study shows that seasonal changes in sunshine account for variations in the number of suicides and especially violent suicides. We propose that sunshine, via interactions with serotonin neurotransmission, may trigger increased impulsivity and promote suicidal acts. However, because of the hypothesis-generating design of this study, more research is needed to further clarify the role of sunshine in triggering neurobiologic changes, which might contribute to suicidal behavior.

Temperature change dominates the suicidal seasonality in Taiwan: a time-series analysis

OBJECTIVE

The arguments between bioclimatic and sociodemographic hypotheses for the suicidal seasonality continue. The present study aimed to examine the relationships between suicidal seasonality and the climate as well as the economic factors.

METHODS

The monthly suicide death rates of the total, male and female populations in Taiwan during January 1991-December 2010 were obtained from the population-based database. Autoregressive integrated moving average (ARIMA)/seasonal ARIMA (SARIMA) was used to analyze suicidal seasonality, with monthly ambient temperature, temperature increase, rainfall, sunlight, unemployment and labor force participation rates as the independent inputs.

RESULTS

The models revealed that monthly temperature increase was strongly positively associated with seasonality of suicide rates of all populations (β=0.0184, P<0.001; β=0.0234, P=0.001; β=0.0145, P<0.001, respectively). Rainfall was significantly negatively associated with the total and male suicide rates (β=-0.0001, P=0.012; β=-0.0002, P=0.043, respectively), but not with female. Unemployment and labor force participation rates were not significantly related to their corresponding suicide rates.

LIMITATIONS

Socio-demographic data, individual major events, and subgroups by suicide methods were not taken into account.

CONCLUSIONS

The results indicate that, as far as suicidal seasonality is concerned, monthly temperature increase is the most influential factor, and climatic factors have more significant effect than the economic factors.

Association between daily environmental temperature and suicide mortality in Korea (2001-2005)

Little attention has been paid to whether temperature is associated with suicide and to whether suicide seasonality appears in Asian countries as shown in Western countries, even though suicide rates in Korea have increased steadily. The goal of the present study was to examine the association between daily temperature and daily suicide rate in Korea, taking gender, age, and education level into account. Data were analyzed using a generalized additive model, adjusting for confounding factors such as sunshine, relative humidity, holidays, and long-term trends. Suicide rates were higher in spring and summer than other seasons. We observed a 1.4% increase (95% confidence interval=1.0-1.7%) in suicide with each 1°C-increase in daily mean temperature. The suicide risks related to the temperature for males, elderly people, and those with less education were higher than for females, younger people, and those with more education, respectively. These findings have confirmed that temperature is associated with suicide in Korea and further our understanding of more susceptible groups, the effects of gender, age, and education level. Therefore, temperature, one of the meteorological factors, is an important risk factor on suicide.

Re-examination of the seasonality of suicide in Taiwan during 1991-2008: a population-based study

The purpose of the present study was to re-examine the monthly distribution of suicide death rates and the change of the suicide seasonality in Taiwan during 1991-2008. The monthly suicide death rates of the total, male and female populations during January 1991-December 2008 were obtained from a population-based database. There was an upward trend. The means of the monthly suicide rates after adjusting the calendar effect and the upward trend were compared. The suicide data were further analysed in three 6-year periods to explore the change of seasonality. During 1991-2008 in Taiwan, suicide rates had significant peaks in April and May, and nadirs in January and December. The monthly distributions varied during 1991-1996, 1997-2002 and 2003-2008 in the patterns and the statistical significance. There was no linear trend for the change of the seasonality of suicide death rate.

The secular trend of suicide rate and the socio-economic, media, and climatic factors in Taiwan, 1976-2009: a population-based study

INTRODUCTION

The purpose of the present study was to explore the relationship between the secular trend of the suicide rate and the socio-economic, media, and climatic factors in Taiwan during 1976-2009.

METHODS

The yearly suicide death rate, socio-economic (spouseless population, aged population, labor participation rate, unemployment rate, and gross national production), media (newspapers, television sets, and personal computer) densities, and climatic (temperature, rainfall, and sunshine) factors were gathered. Pearson's correlation coefficients between variables were calculated, and stepwise multiple regression analysis was conducted.

RESULTS

Percentage of the spouseless and elderly population, labor participation rate, unemployment rate, and densities of newspapers and personal computer were significantly associated with suicide rate. Multiple regression chose spouseless population, labor participation rate, and unemployment rate to explain 96.1% of the variance of the suicide rate (F((3,22))=178.996, p=0.000).

CONCLUSIONS

Socio-economic factors are important for the secular trend of suicide, while medium densities also play some roles.