Relationship between daily suicide counts and temperature in England and Wales

Self-harm and interpersonal violence due to high temperature from the global burden of disease study 2019: A 30-year assessment

BACKGROUND

The impact of global warming on health due to climate change is increasingly studied, but the global burden of self-harm and interpersonal violence attributable to high temperature is still limited. This study aimed to systematically assess the burden of self-harm and interpersonal violence attributable to high temperature globally or by region and climate zone from 1990 to 2019.

METHODS

We obtained the global, regional, and national deaths, disability-adjusted life years (DALYs), age-standardized mortality rates (ASMR), and age-standardized disability-adjusted life year rates (ASDR) of self-harm and interpersonal violence due to high temperature from 1990 to 2019 through the Global Burden of Disease Study (GBD) 2019. The burden of self-harm and interpersonal violence due to high temperature was estimated by age, sex, climate zone, the socio-demographic index (SDI), and the healthcare access and quality index (HAQ). Average annual percentage changes (AAPCs) in ASMR and ASDR were calculated for 1990-2019 using the Joinpoint model.

RESULTS

From 1990 to 2019, the global deaths and DALYs related to self-harm and interpersonal violence due to high temperature increased from 20,002 (95% UI, 9243 to 41,928) and 1,107,216 (95% UI, 512,062 to 2,319,477) to 26,459 (95% UI, 13,574 to 47,265) and 1,382,487 (95% UI, 722,060 to 2,474,441), respectively. However, the ASMR and ASDR showed varying degrees of decreasing trends, with decreases of 13.36% and 12.66%, respectively. The ASMR was high and declining in low and low-middle SDI regions, particularly in tropical and subtropical regions. In addition, SDI and HAQ index were negatively correlated with ASMR in 204 countries and regions.

CONCLUSIONS

The global burden of self-harm and interpersonal violence attributed to high temperature has decreased over the past 30 years, but the number of deaths and DALYs continues to rise. Climate change continues to make heat stress a significant risk factor for self-harm and interpersonal violence worldwide.

Economic activity and suicides: Causal evidence from macroeconomic shocks in England and Wales

The relationship between economic activity and suicides has been the subject of much scrutiny, but the focus in the extant literature has been almost exclusively on estimating associations rather than causal effects. In this paper, using data from England and Wales between January 1, 1997 and December 31, 2017, we propose a plausible set of assumptions to estimate the causal impacts of well-known macroeconomic variables on the daily suicide rate. Our identification strategy relies on scheduled macroeconomic announcements and professional economic forecasts. An important advantage of using these variables to model suicide rates is that they can efficiently capture the elements of 'surprise or shock' via the observed difference between how the economy actually performed and how it was expected to perform. Provided that professional forecasts are unbiased and efficient, the estimated 'surprises or shocks' are 'as good as random', and therefore are exogenous. We employ time series regressions and present robust evidence that these exogenous macroeconomic shocks affect the suicide rate. Overall, our results are consistent with economic theory that shocks that reduce estimated permanent income, and therefore expected lifetime utility, can propel suicide rates. Specifically, at the population level, negative shocks to consumer confidence and house prices accelerate the suicide rate. However, there is evidence of behavioural heterogeneity between sexes, states of the economy, and levels of public trust in government. Negative shocks to the retail price index (RPI) raise the suicide rate for males. Negative shocks to the growth rate in gross domestic product (GDP) raise the population suicide rate when the economy is doing poorly. When public trust in government is low, increases in the unemployment rate increase the suicide rate for females.

Impacts of compounding drought and heatwave events on child mental health: insights from a spatial clustering analysis

BACKGROUND

Concurrent heatwave and drought events may have larger health impacts than each event separately; however, no US-based studies have examined differential mental health impacts of compound drought and heatwave events in pediatric populations.

OBJECTIVE

To examine the spatial patterns of mood disorders and suicide-related emergency department (ED) visits in children during heatwave, drought, and compound heatwave and drought events. We tested whether the occurrence of compound heatwave and drought events have a synergistic (multiplicative) effect on the risk of mental health related outcomes in children as compared to the additive effect of each individual climate hazard. Lastly, we identified household and community-level determinants of geographic variability of high psychiatric burden.

METHODS

Daily counts of psychiatric ED visits in North Carolina from 2016 to 2019 (May to Sept) for pediatric populations were aggregated at the county scale. Bernoulli cluster analyses identified high-risk spatial clusters of psychiatric morbidity during heatwave, drought, or compound heatwave and drought periods. Multivariate adaptive regression models examined the individual importance of household and community-level determinants in predicting high-risk clustering of mood disorders or suicidality across the three climate threats.

RESULTS

Results showed significant spatial clustering of suicide and mood disorder risks in children during heatwave, drought, and compound event periods. Periods of drought were associated with the highest likelihood of spatial clustering for suicide and mood disorders, where the risk of an ED visit was 4.48 and 6.32 times higher, respectively, compared to non-drought periods. Compounding events were associated with a threefold increase in both suicide and mood disorder-related ED visits. Community and household vulnerability factors that most contributed to spatial clustering varied across climate hazards, but consistent determinants included residential segregation, green space availability, low English proficiency, overcrowding, no broadband access, no vehicle access, housing vacancy, and availability of housing units.

CONCLUSION

Findings advance understanding on the locations of vulnerable pediatric populations who are disproportionately exposed to compounding climate stressors and identify community resilience factors to target in public health adaptation strategies.

The Influence of Ambient Weather Conditions on Stated Preferences for Ecosystem Services Management

One of the assumptions in stated preference studies is the stability of respondents' preferences. This assumption might be violated in situations of context dependence, i.e., when the contingent situation influences respondents' choices. Ambient weather conditions (AWCs) are one element of the context that may influence stated preferences. The literature suggests that AWCs affect people's emotions, behaviors, and decision-making processes; however, the potential AWCs impact in environmental preference studies has not yet been investigated. This aspect is of high importance because context-dependent choices return biased willingness to pay estimates and affect the subsequent welfare analysis that informs public policy. To shed light on this important aspect of non-market valuation studies, we explore the effect of AWCs on preferences elicited with a Discrete Choice Experiment for ecosystem services management of a Nature Park. Results of a generalized mixed logit model evidenced a significant effect of AWCs on respondents' choices, with good weather conditions leading to higher preferences and willingness to pay for ecosystem services management. This result, which is consistent with previous psychological studies, raises the issue of sampling design and reveals the importance of a sensitivity analysis of WTP. As this issue is still unexplored in stated preference studies, we also encourage undertaking similar studies to add a priori knowledge for more accurate ex-post calibration of WTP estimates.

Prevention of suicides associated with global warming: perspectives from early career psychiatrists

Climate change poses significant challenges to global mental health, with potential consequences including increased rates of suicide and mental health disorders. Early Career Psychiatrists (ECPs) play a crucial role in addressing these challenges. The Climate Psychiatry Alliance, a group of psychiatrists dedicated to improving mental health amidst climate change, recognizes the importance of cultivating climate-aware ECPs. Training ECPs to become confident climate-aware clinicians enables them to effectively treat patients experiencing anxiety, depression, and PTSD in the context of climate-related distress. Together with other mental health professionals, ECPs can contribute to efforts by implementing strategies for monitoring and treating mental health problems arising from climate events. Additionally, they can raise awareness about the psychological consequences and risks of suicide associated with climate change. Collaboration among ECPs from various regions is essential in developing community-based approaches and reducing vulnerabilities. ECPs must prioritize supporting vulnerable populations by advocating for increased funding for mental health support and research in affected areas. Long-term solutions to address the mental health impacts of climate change and global warming should be pursued to mitigate future suicidality. Integrating climate considerations into local mental health programs and expanding psychological support services is crucial. By promoting emotional resilience and self-awareness, ECPs can contribute to building a more climate-resilient and mentally healthy society.

Youth Suicidality in the Context of Disasters

PURPOSE OF REVIEW

The purpose of this review is to summarize the current literature regarding youth suicidality (suicidal ideation, suicidal behavior, and completed suicide) in the context of disasters.

RECENT FINDINGS

There are fewer studies that examine the effect of disasters on suicidality specifically in children and youth than studies that focus on adults or general population. Numerous studies have reported on the effect of disasters on youth mental health in general without zeroing in on suicide risk. Some variables that have shown to increase suicide risk in children and youth after disasters include female gender, age at the time of disaster exposure, dependence on adults, attachments to places and caregivers, family functioning, and vulnerability to mistreatment. Several studies have demonstrated that youth suicidality fluctuates in response to disasters, at times increasing immediately post-disaster and at other times decreasing immediately post-disaster followed by an increase later. Exposure to natural disasters (e.g., earthquakes, typhoons, hurricanes, wildfires, and extremes of temperature and humidity), man-made disasters (e.g., armed conflict, global warming, and pollution), and unique disasters (e.g., the COVID-19 pandemic) have had significant impact on suicidality in children and adolescents. Although there are several promising interventions to mitigate the post-disaster suicide risk among youth, there is no consensus on a single intervention that is superior to others. More research is needed to study youth suicide risk in the context of disasters and develop culturally appropriate and evidence-based interventions.

Characteristics and related factors of suicide attempts among patients admitted to an Iranian poisoning center: Implications for suicide prevention

Background

Suicide is a major public health concern worldwide. Iran is no exception, with suicide rates increasing in recent years. Understanding the characteristics and related factors of suicide attempts can help inform suicide prevention efforts in Iran.

Methods

A cross-sectional study was conducted on patients who attempted suicide and were admitted to the poisoning emergency of an intoxication center in Shiraz, Iran, between November 2019 and January 2020. Data were collected using data sheets containing study variables completed by oral interviewers and analyzed using descriptive and inferential statistics.

Results

The study included 302 individuals, with the majority being females (63.6%), and the mean age was 28.19 (SD 19.25) years. The majority of patients were living in urban areas (82.5%) and unmarried (60.9%). Medical drug abuse was the most common method of self-poisoning (76.5%), followed by narcotics (15.6%). Suicide attempts were predominantly carried out at night (59.9%) and on working days (78.5%). Most patients had no history of previous suicidal attempts (64.2%), psychiatric problems (64.6%), or physical illnesses (84.8%). Female gender (P = 0.017) and the presence of an underlying disease (P = 0.016) were the two risk factors significantly associated with suicide on non-working days.

Conclusion

Our study highlights the need for comprehensive suicide prevention strategies that consider the complex interplay of individual, sociocultural, and environmental factors that contribute to suicidal behaviors. The high proportion of female suicide attempters and the timing of suicide attempts suggest the need for gender-specific suicide prevention programs and focused suicide prevention efforts during high-risk periods. Additionally, the association between physical illnesses and suicide attempts underscores the importance of integrated mental and physical health care services.

Ambient temperature and mental health: a systematic review and meta-analysis

BACKGROUND

Increasing evidence indicates that ambient outdoor temperature could affect mental health, which is especially concerning in the context of climate change. We aimed to comprehensively analyse the current evidence regarding the associations between ambient temperature and mental health outcomes.

METHODS

We did a systematic review and meta-analysis of the evidence regarding associations between ambient outdoor temperature and changes in mental health outcomes. We searched WebOfScience, Embase, PsychINFO, and PubMed for articles published from database origin up to April 7, 2022. Eligible articles were epidemiological, observational studies in humans of all ages, which evaluated real-world responses to ambient outdoor temperature, and had mental health as a documented outcome; studies of manipulated or controlled temperature or those with only physical health outcomes were excluded. All eligible studies were synthesised qualitatively. If three or more studies reported the same or equivalent effect statistics and if they had equivalent exposure, outcome, and metrics, the studies were pooled in a random-effects meta-analysis. The risk of bias for individual studies was assessed using the Newcastle-Ottawa Scale. The quality of evidence across studies was assessed using the Office of Health Assessment and Translation (OHAT) approach.

FINDINGS

114 studies were included in the systematic review, of which 19 were suitable for meta-analysis. Three meta-analyses were conducted for suicide outcomes: a 1°C increase in mean monthly temperature was associated with an increase in incidence of 1·5% (95% CI 0·8-2·2, p<0·001; n=1 563 109, seven effects pooled from three studies); a 1°C increase in mean daily temperature was associated with an increase in incidence of 1·7% (0·3-3·0, p=0·014; n=113 523, five effects pooled from five studies); and a 1°C increase in mean monthly temperature was associated with a risk ratio of 1·01 (95% CI 1·00-1·01, p<0·001; n=111 794, six effects pooled from three studies). Three meta-analyses were conducted for hospital attendance or admission for mental illness: heatwaves versus non-heatwave periods were associated with an increase in incidence of 9·7% (95% CI 7·6-11·9, p<0·001; n=362 086, three studies); the risk ratio at the 99th percentile of daily mean temperature compared with the 50th percentile was 1·02 (95% CI 1·01-1·03, p=0·006; n=532 296, three studies); and no significant association was found between a 10°C increase in daily mean temperature and hospital attendance. In a qualitative narrative synthesis, we found that ambient outdoor temperature (including absolute temperatures, temperature variability, and heatwaves) was positively associated with attempted and completed suicides (86 studies), hospital attendance or admission for mental illness (43 studies), and worse outcomes for community mental health and wellbeing (19 studies), but much of the evidence was of low certainty with high heterogeneity.

INTERPRETATION

Increased temperature and temperature variability could be associated with increased cases of suicide and suicidal behaviour, hospital attendance or admission for mental illness, and poor community health and wellbeing. Climate change is likely to increase temperature anomalies, variability, and heatwaves as well as average temperatures; as such, health system leaders and policy makers must be adequately prepared and should develop adaptation strategies. More high-quality, standardised research is required to improve our understanding of these effects.

FUNDING

None.

Qualitative research in suicidology: a systematic review of the literature of low-and middle-income countries

BACKGROUND

Suicide is more prevalent among disadvantaged, discriminated, and marginalised people with the majority of global suicide deaths occurring in the low-and middle-income countries (LMICs). This can be attributed to sociocultural contexts and exacerbated by access to limited resources and services that can assist with early identification, treatment, and support. Accurate information on the personal experiences of suicide is lacking, as many LMICs legislate that suicide is illegal.

METHODS

This study aims to review the qualitative literature to explore the experiences of suicide in LMICs from the first-person perspective. Following the PRISMA-2020 guidelines, the search for qualitative literature published between January 2010 and December 2021 was undertaken. A total number of 110 qualitative articles from 2569 primary studies met the inclusion criteria. Included records were appraised, extracted, and synthesised.

RESULTS

The results provide lived experience insight into suicide from those living in LMICs, including understanding variations of the causes of suicides, the impacts on others exposed to suicide, existing support systems, and prevention measures to reduce suicide among LMICs. The study offers a contemporaryunderstanding of how people in LMIC experience suicide.

CONCLUSIONS

The findings and recommendations are derived from the similarities and differences within the existing knowledge base that is dominated by evidence from high-income countries. Timely suggestions for future researchers, stakeholders, and policymakers are provided.

Assessing the Burden of Suicide Death Associated With Nonoptimum Temperature in a Changing Climate

Importance

Few studies have projected future suicide burden associated with daily temperatures in a warming climate.

Objectives

To assess the burden of suicide death associated with daily nonoptimal temperature and to project the change of suicide burden associated with nonoptimal temperature in different regions and seasons under various climate change scenarios.

Design, Setting, and Participants

Between January 1, 2013, and December 31, 2019, we conducted a time-stratified, case-control study among more than 430 000 individual suicide decedents from all counties in mainland China.

Exposures

Daily meteorological data were obtained from the European Centre for Medium-Range Weather Forecasts Reanalysis Fifth Generation (ERA5) reanalysis product. Historical and future temperature series were projected under 3 scenarios of greenhouse-gas emissions from 1980 to 2099, with 10 general circulation models.

Main Outcomes and Measures

The relative risk (RR) and burden of suicide death associated with nonoptimal temperature (ie, temperatures greater than or less than minimum-mortality temperature); the change of suicide burden associated with future climate warming in different regions and seasons under various climate change scenarios.

Results

Of 432 008 individuals (mean [SD] age; 57.6 [19.0] years; 253 093 male [58.6%]) who died by suicide, 85.8% (370 577) had a middle school education or less. The temperature-suicide associations were approximately linear, with increasing death risks at higher temperatures. The excess risk was more prominent among older adults (ie, ≥75 years; RR, 1.71; 95% CI, 1.46-1.99) and those with low education level (ie, middle school education or less; RR, 1.46; 95% CI, 1.36-1.57). There were 15.2% suicide deaths (95% estimated CI [eCI], 14.6%-15.6%) associated with nonoptimal temperature nationally. Consistent and drastic increases in excess suicide deaths over this century were predicted under the high-emission scenario, whereas a leveling-off trend after the mid-21st century was predicted under the medium- and low-emission scenarios. Nationally, compared with the historical period (1980-2009), excess suicide deaths were predicted to increase by 8.3% to 11.4% in the 2050s and 8.5% to 21.7% in the 2090s under the 3 scenarios. The projected percentage increments of excess suicide deaths were predicted to be greater in the South (55.0%; 95% eCI, 30.5%-85.6%) and in winter (54.5%; 95% eCI, 30.4%-77.0%) in the 2090s under the high-emission scenario.

Conclusions and Relevance

Findings of this nationwide case-control study suggest that higher temperature may be associated with the risk and burden of suicide death in China. These findings highlight the importance of implementing effective climate policies to reduce greenhouse gas emissions and tailoring public health policies to adapt to global warming.

Heatwave and mental health

Physical health has been associated with ambient temperature and heatwave. With the frequent occurrence of heatwave, the adaptive effects and mechanisms on mental health remain uncertain. On the basis of the China Health and Nutrition Survey, we estimated the relationship between heatwaves and self-assessed mental health scores in the Chinese population aged 50 and above. This study has identified that with each additional heatwave event, mental health scores decreased by an average of 0.027 points, which is equivalent to 0.3% of the average level. Heat is more likely to affect groups with low education, no medical insurance, and living in rural areas. In mechanistic exploration, we found that stress emotion is a fully mediating effect. Heat led to reduced health activities and more frequent drinking, which may lead to lower psychological well-being. Moreover, good dietary preference is a regulator that can help mitigate the adverse effects of heat on mental health. This study corroborates the impact of heat on spiritual welfare, and demonstrates the mechanisms and channels of impact, which can help reduce global economic losses due to mental health problems.

Mental health and air temperature: Attributable risk analysis for schizophrenia hospital admissions in arid urban climates

Health researchers have examined the physiological impacts of extreme air temperature on the human body. Yet, the mental health impacts of temperature have been understudied. Research has shown that the environment can create circumstances that exacerbate mental health issues. This may be particularly challenging for some of the fastest growing cities, located in hot, dry climates. Given the theoretical relationship between air temperature and mental health, we seek to measure the association between temperature and schizophrenia hospital admissions in an arid urban climate and quantify the associated public health burden. We collected 86,672 hospitalization records for schizophrenia from 2006 to 2014 in Maricopa County, Arizona, USA. Using a distributed lag non-linear model (DLNM), we tested for a statistical association between temperature and schizophrenia hospital admissions after controlling for year, season, weekends, and holidays. We calculated the cumulative attributable risk of nighttime temperature on schizophrenia for the entire dataset as well as among demographic subgroups. The relative risk of schizophrenia hospital admissions increased with both high and low temperatures. Statistical models using daily minimum temperature were more strongly associated with hospitalization than those using mean or maximum. Schizophrenia hospital admissions increased on days with minimum temperatures above 30 °C and below 3 °C, with some subgroups experiencing higher rates of hospitalization. The total fraction of schizophrenia hospital admissions attributable to non-optimal minimum temperature is 3.45 % (CI: -4.91-10.80 %) and high minimum temperature is 0.28 % (CI: -1.18-1.78 %). We found that non-whites and males appear to be at a slightly increased risk than the general population, although there did not appear to be a statistically significant difference. A conservative estimate of healthcare costs annually from non-optimal temperature attributed schizophrenia hospitalization is $1.95 million USD. Therefore, nighttime cooling strategies and efforts could increase the accessibility of shelters to reduce overnight exposure to extreme air temperature.

Climate change and mental health: time for action and advocacy

Climate change poses an existential threat to our planet and our health. We explore the intersections of climate change and mental health which has been under-recognised to date. Climate change can affect mental health directly through the effects of extreme weather events such as heat, drought and flooding, and indirectly through increasing rates of migration and inequality. Vulnerable individuals with neuropsychiatric disorders will be particularly at risk. Emerging evidence is also showing effects of air pollution on brain development. Mitigation efforts related to reducing carbon emissions will have both direct and indirect effects on mental health. A further consideration demonstrated by the COVID-19 pandemic is that the spread of infectious disease can have substantial effects on the mental health of the population. With climate change and biodiversity loss, pandemics could recur in the future with increasing frequency. It is now essential that mental health professionals be equipped as agents for climate action.

Long-Term Apparent Temperature, Extreme Temperature Exposure, and Depressive Symptoms: A Longitudinal Study in China

Temperature is increasingly understood to impact mental health. However, evidence of the long-term effect of temperature exposure on the risk of depressive symptoms is still scarce. Based on the China Health and Retirement Longitudinal Study (CHARLS), this study estimated associations between long-term apparent temperature, extreme temperature, and depressive symptoms in middle-aged and older adults. Results showed that a 1 °C increase or decrease from optimum apparent temperature (12.72 °C) was associated with a 2.7% (95% CI: 1.3%, 4.1%) and 2.3% (95% CI: 1.1%, 3.5%) increased risk of depressive symptoms, respectively. This study also found that each percent increase in annual change in ice days, cool nights, cool days, cold spell durations, and tropical nights was associated with higher risk of depressive symptoms, with HRs (95%CI) of 1.289 (1.114-1.491), 2.064 (1.507-2.825), 1.315 (1.061-1.631), 1.645 (1.306-2.072), and 1.344 (1.127-1.602), respectively. The results also indicated that people living in northern China have attenuated risk of low apparent temperature. Older people were also observed at higher risk relating to more cool nights. Middle-aged people, rural residents, and people with lower household income might have higher related risk of depressive symptoms due to increased tropical nights. Given the dual effect of climate change and global aging, these findings have great significance for policy making and adaptive strategies for long-term temperature and extreme temperature exposure.

A Systematic Literature Review of the Impact of Climate Change on the Global Demand for Psychiatric Services

Climate Change (CC) imposes important global health risks, including on mental health (MH). They are related mostly to psychological suffering caused by climate-related events and to the heat-vulnerability caused by psychiatric disorders. This growing burden may press MH services worldwide, increasing demand on public and private systems in low-, middle-, and high-income countries. According to PRISMA, two independent reviewers searched four databases for papers published before May 2022 that associated climate-related events with healthcare demand for psychiatric conditions. Of the 7432 papers retrieved, we included 105. Only 29 were carried out in low- and middle-income countries. Twelve related the admission numbers to (i) extreme events, while 93 to (ii) meteorological factors-mostly heat. Emergency visits and hospitalizations were significantly higher during hot periods for MH disorders, especially until lag 5-7. Extreme events also caused more consultations. Suicide (completed or attempted), substance misuse, schizophrenia, mood, organic and neurotic disorders, and mortality were strongly affected by CC. This high healthcare demand is evidence of the burden patients may undergo. In addition, public and private services may face a shortage of financial and human resources. Finally, the increased use of healthcare facilities, in turn, intensifies greenhouse gas emissions, representing a self-enforcing cycle for CC. Further research is needed to better clarify how extreme events affect MH services and, in addition, if services in low- and middle-income countries are more intensely demanded by CC, as compared to richer countries.

The Impact of Extreme Temperature Shocks on the Health Status of the Elderly in China

With the accelerating process of climate change, long-term exposure to extreme temperatures could threaten individuals' physical health, especially for the vulnerable population. This paper aims to investigate the long-term effects of extreme temperature exposure on the health of the elderly in the context of climate change and aging. Different from most of the existing literature in environmental economics, we define the relative extreme temperature exposure based on the local temperature pattern. By combining a large national household survey and nationwide meteorologic historical data, this study provides empirical evidence that heat exposure days and cold exposure days during the past year both significantly affect the physical health of middle-aged and elderly groups, controlling for city, year, and individual fixed effects. The effect on individual physical health has certain seasonal characteristics and is heterogeneous across populations. Additionally, cooling and heating equipment are effective in alleviating the reverse impact of heat and cold exposure. The estimation is robust and consistent across a variety of temperature measurements and model modifications. Our findings provide evidence of the long-term and accumulative cost of extreme temperature to middle-aged and elderly human capital, contributing to helping the public to better understand the full impact of climate change.

Association of Daily Temperature With Suicide Mortality: A Comparison With Other Causes of Death and Characterization of Possible Attenuation Across 5 Decades

Suicide is one of the leading causes of death in young adults in many Western countries. We examined the short-term association of temperature with cause-specific mortality, comparing suicide with other causes of death and describing possible attenuation of associations with temperature across decades. We considered all deaths that occurred in France between 1968 and 2016. For each cause of death, we conducted a 2-stage meta-analysis of associations with daily temperature. We stratified the association across time periods. A total of 502,017 deaths by suicide were recorded over 49 years. Temperature was monotonically associated with suicide mortality. The strongest association was found at lag 0 days. The relative risk of suicide mortality at the 99th (compared with the 1st) temperature percentile was 1.54 (95% confidence interval, 1.46, 1.63). Among all causes of death, suicide was the only cause displaying a monotonic trend with temperature and ranked seventh for heat-related mortality; 2 other causes of death implying the nervous system ranked third and fourth. Associations with temperature attenuated between the 1968-1984 and 1985-2000 periods for all-cause mortality and suicide mortality, without clear further attenuation in the 2001-2016 period. The robust short-term monotonic association between temperature and suicide risk could be considered in heat effects- and suicide-related prevention campaigns.

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.

Supplementary information

The online version contains supplementary material available at https://doi.org/10.1265/ehpm.21-00044.

Current understanding of the impact of climate change on mental health within UK parliament

There is growing evidence that climate change is linked to adverse mental health outcomes, with both direct and indirect impacts already being felt globally, including within the United Kingdom (UK). With the UK parliament tasked with passing legislation to mitigate against and adapt to climate change, it is well placed to take a lead in implementing policies that reduce the impact of climate change on mental health and even provide mental health benefits (e.g., by increasing access to green space). The extent to which the UK parliament considers the relationship between climate change and mental health in its decision-making was previously unknown. We report, through quantitative thematic analysis of the UK Hansard database, that the UK parliament has only infrequently made links between climate change and mental health. Where links have been made, the primary focus of the speeches were around flooding and anxiety. Key mental health impacts of climate change reported in the academic literature, such as high temperature and suicides, or experiences of eco-anxiety, were found to be missing entirely. Further, policies suggested in UK parliament to minimise the impact of climate change on mental health were focused on pushing adaptation measures such as flood defences rather than climate mitigation, indicating potential missed opportunities for effective policies with co-benefits for tackling climate change and mental health simultaneously. Therefore, this research suggests a need to raise awareness for UK policymakers of the costs of climate inaction on mental health, and potential co-benefits of climate action on mental health. Our results provide insight into where links have and have not been made to date, to inform targeted awareness raising and ultimately equip policymakers to protect the UK from the increasingly large impacts of climate change on mental health.

Main and added effects of heatwaves on hospitalizations for mental and behavioral disorders in a tropical megacity of Vietnam

Vietnam is highly vulnerable to climate change-related extreme weather events such as heatwaves. This study assesses the association between heatwaves and hospitalizations due to mental and behavioral disorders (MBDs) in Ho Chi Minh City (HCMC). We collected daily MBD hospital admissions data at the HCMC Mental Health Hospital from 2017 to 2019. Heatwaves effects were characterized into the main effect (i.e., the intensity of temperature during heatwaves) and the added effect (i.e., the duration of heatwaves). Time series Poisson regression coupled with a distributed lag linear model (DLM) was used to quantify the 14-day lags effect of heatwaves. Confounders including long-term trend, seasonality, days of the week, holidays, and relative humidity were included in the model. Heatwaves increased all-cause MBD hospitalization by 62% (95%Cl, 36-93%) for the main effect and by 8% (95% Cl, - 3% to 19%) for the added effect. Noticeably, the group aged 18-60 years old was affected by the main effect of the heatwave, while the group aged 61 years and older was affected by the added effect of the heatwave. The effects of heatwaves differed among groups of MBD hospitalizations. The mental and behavioral disorder group due to psychoactive substance use was significantly affected by the main effect of heatwaves (RR:2.21; 95%Cl:1.55-3.15). The group of schizophrenia, schizotypal and delusional disorders were highly vulnerable towards both the main and the added effect of heatwaves with RR = 1.50 (95%CI, 1.20-1.86) and RR = 1.14 (95%CI, 1.01-1.30), respectively.

Climate Change Related Depression, Anxiety and Stress Symptoms Perceived by Medical Students

Climate change has drastic consequences on human physical and mental health. However, research on the psychological effects of climate change awareness is still inconclusive. To examine the mental burden posed by climate change awareness and potential resilience factors, n = 203 medical students were surveyed about their awareness of the implications of climate change. Furthermore, well-established mental health questionnaires (PHQ-9, GAD-7, PTSS-10, PSQ-20) were presented twice, in their original form and in a modified version to specifically ask about the respective psychological burden regarding climate change. For identification of potential resilience factors, measures for attachment style (RQ), structural abilities (OPD-SF), and sense of coherence (SOC-13) were used. The results of our study suggest that medical students in Germany have an increased risk to suffer from mental health problems and predominantly experience significant perceived stress in regard to climate change. However, the reported stress does not yet translate into depressive, anxious, or traumatic symptoms. Climate-related perceived stress correlates negatively with potential resilience factors preventing the development of mental disorders such as attachment style, structural abilities, and sense of coherence.

The need for location-specific biometeorological indexes in Taiwan

Objective

As most available biometeorological indexes were developed decades ago in western countries, the benefit of using these indexes to study the effect of weather on human health in modern eastern countries is questionable. This study aimed to reconfirm the effectiveness of applying these biometeorological indexes when analyzing demand for daily emergency ambulance services (EAS) in Taipei.

Methods

More than 370,000 EAS usage records were analyzed in this study. The records were first allotted into different time-series data by age, gender, triage level, and case nature (trauma/non-trauma) in order to represent different kinds of daily EAS demand. They were then regressed on biometeorological indexes [Apparent Temperature (AT) and Net Effective Temperature (NET)]; the indexes' additional descriptive power to describe the daily EAS demand over traditional weather factors was then assessed.

Results

No significant difference was observed in the descriptive powers in terms of effect on daily EAS demand of the biometeorological indexes and traditional weather factors. The largest improvement on the regression models' adjusted-R2 using NET and AT was only 0.008.

Conclusion

It may not be a good idea to make direct use of the biometeorological indexes developed in western countries decades ago. Taiwan should have a tailor-made biometeorological index for a better representation of its unique situation.

Short-term changes in meteorological conditions and suicide: A systematic review and meta-analysis

BACKGROUND

Suicide is a leading cause of death, particularly for young adults. Suicidal behaviours are influenced by a wide-range of personal, social, and cultural factors. Emerging evidence suggests that daily changes in meteorological conditions, including temperature, increases the risk of suicide.

METHODS

We conducted a systematic review and meta-analysis of studies that examined associations between either daily, or weekly, variations for eight meteorological variables and suicide outcomes (attempts, or deaths). Meta-analytic methods were applied to derive summary measures of association using random effect models. We assessed the heterogeneity in these associations by region and biological sex.

RESULTS

We identified 29 studies of suicide. Of these, 26 reported associations between temperature, while fewer studies reported on rain (n = 4), solar radiation (n = 4), humidity (n = 3), sunshine (n = 3), atmospheric pressure (n = 2), wind (n = 2) and cloud cover (n = 2). The overall relative risk for suicide deaths/attempts per 1 °C increase in ambient temperature was 1.016 (95% CI: 1.013-1.019). Subgroup analysis of temperature found stronger associations with suicide when using the maximum rather than the mean daily temperature, among men, and for completed suicides relative to attempts. Regionally, the strongest associations were found in the East Asia and Pacific region. While associations were found for solar radiation and cloud coverage and suicide, we did not undertake a meta-analysis for these exposures as it was not possible to standardize measures of association across studies. Statistically significant associations were not observed for other identified meteorological variables.

CONCLUSIONS

Our findings suggest that daily increases in temperature increase the risk of suicide, particularly, among men and in the East Asia and Pacific region.

High temperatures trigger suicide mortality in Brussels, Belgium: A case-crossover study (2002-2011)

BACKGROUND

Temperature may trigger the risk of suicide, however, the extent and shape of the associations show geographical variation. Here, we investigate the short-term effects of temperature on suicide deaths occurring in Brussels between January 1st, 2002 and December 31st, 2011.

METHODS

We conducted a bidirectional time-stratified case-crossover study with cases being suicide deaths occurring among Brussels residents aged 5 years or older. Cases were matched by day of the week with control days from the same month and year. The exposure was the daily average temperature measured at the Uccle station (Brussels) and obtained from the Belgian Royal Meteorological Institute. We combined conditional logistic regression with distributed lag non-linear models (DLNM) to obtain one week (lag 0-6) cumulative risk ratios (RR) and their 95% confidence intervals (CI) for the effects of moderate and extreme cold (5th and 1st percentiles of temperature, respectively) and moderate and extreme heat (95th and 99th percentiles of temperature, respectively), relative to the median temperature.

RESULTS

In total, 1891 suicide deaths were included. The median temperature was 11.6 °C, moderate and extreme cold temperatures were 0 and -3.1 °C, respectively, and moderate and extreme high temperatures were 20.9 and 24.4 °C, respectively. The cumulative risk of suicide mortality was almost twice higher among lags 0 to 6 for both moderate and extreme heat, relative to the period median temperature (e.g. moderate heat RR = 1.80 CI:1.27-2.54). No statistically significant associations were observed for cold temperatures.

CONCLUSIONS

In Brussels, a western European city with temperate climate, high temperatures may trigger suicide deaths up to one week later. In the context of climate change, adaptation strategies must take into consideration the effects of temperature on mental health.

Climate change and mental health research methods, gaps, and priorities: a scoping review

Research on climate change and mental health is a new but rapidly growing field. To summarise key advances and gaps in the current state of climate change and mental health studies, we conducted a scoping review that comprehensively examined research methodologies using large-scale datasets. We identified 56 eligible articles published in Embase, PubMed, PsycInfo, and Web of Science between Jan 1, 2000, and Aug 9, 2020. The primary data collection method used was surveys, which focused on self-reported mental health effects due to acute and subacute climate events. Other approaches used administrative health records to study the effect of environmental temperature on hospital admissions for mental health conditions, and national vital statistics to assess the relationship between environmental temperature and suicide rates with regression analyses. Our work highlights the need to link population-based mental health outcome databases to weather data for causal inference. Collaborations between mental health providers and data scientists can guide the formation of clinically relevant research questions on climate change.

The impact of macroeconomic factors on suicide in 175 countries over 27 years

BACKGROUND

Every year, more than 800,000 people die by suicide, three-quarters of which are males. Economic factors influence suicide rates, but a worldwide perspective of their impact according to age and sex is lacking.

METHOD

We queried publicly available datasets on economic factors and on suicide rates stratified according to sex and age, from 1991 to 2017, for 175 countries. Thus, we analyzed approximately 21 million deaths by suicide using a multivariable regression model approach.

RESULTS

Every 1% increase in global unemployment rates is associated with a 1% upsurge in male deaths by suicide (Relative risk (RR) = 1.01 [CI 95% 1.00-1.01] with respect to females) or 5000 excess male deaths. A 1% higher unemployment rate also exerts age-specific effects on suicide rates, since, among adults aged 30-59, the suicide rate is increased by 2-3%. Lastly, for every 1000 US dollar increase in the GDP per capita, suicide rates are reduced by 2% (RR = 0.98 [0.98-0.98]), corresponding to a reduction of 14,000-15,000 suicide deaths per year globally.

CONCLUSIONS

Males who have lost their jobs in adulthood are those at higher risk of suicide and to whom financial support measures should be delivered in a timely manner.

Climate change, trauma and mental health in Italy: a scoping review

BACKGROUND

Climate change is having significant impacts on health and mental health across Europe and globally. Such effects are likely to be more severe in climate change hotspots such as the Mediterranean region, including Italy.

OBJECTIVE

To review existing literature on the relationship between climate change and mental health in Italy, with a particular focus on trauma and PTSD.

METHODS

A scoping review methodology was used. We followed guidance for scoping reviews and the PRISMA Extension for Scoping Reviews (PRISMA-ScR) checklist. We searched for literature in MEDLINE, Global Health, Embase and PsycINFO. Following screening, data was extracted from individual papers and a quality assessment was conducted. Given the heterogeneity of studies, findings were summarized narratively.

RESULTS

We identified 21 original research articles investigating the relationship between climate change and mental health in Italy. Climate change stressors (heat and heatwaves in particular) were found to have several negative effects on various mental health outcomes, such as a higher risk of mortality among people with mental health conditions, suicide and suicidal behaviour and psychiatric morbidity (e.g. psychiatric hospitalization and symptoms of mental health conditions). However, there is little research on the relationship between climate change and trauma or PTSD in the Italian context.

CONCLUSIONS

More attention and resources should be directed towards understanding the mental health implications of climate change to prevent, promote, and respond to the mental health needs of Italy and the wider Mediterranean region.

HIGHLIGHTS

• Climate change stressors in Italy were found to have detrimental impacts on various mental health outcomes, such as psychiatric mortality and morbidity. • Little research on the relationship between climate change stressors and PTSD exists in Italy.

Is there an association between hot weather and poor mental health outcomes? A systematic review and meta-analysis

BACKGROUND

Mental health is an important public health issue globally. A potential link between heat exposure and mental health outcomes has been recognised in the scientific literature; however, the associations between heat exposure (both high ambient temperatures and heatwaves) and mental health-related mortality and morbidity vary between studies and locations.

OBJECTIVE

To fill gaps in knowledge, this systematic review aims to summarize the epidemiological evidence and investigate the quantitative effects of high ambient temperatures and heatwaves on mental health-related mortality and morbidity outcomes, while exploring sources of heterogeneity.

METHODS

A systematic search of peer-reviewed epidemiological studies on heat exposure and mental health outcomes published between January 1990 and November 2020 was conducted using five databases (PubMed, Embase, Scopus, Web of Science and PsycINFO). We included studies that examined the association between high ambient temperatures and/or heatwaves and mental health-related mortality and morbidity (e.g. hospital admissions and emergency department visits) in the general population. A range of mental health conditions were defined using ICD-10 classifications. We performed random effects meta-analysis to summarize the relative risks (RRs) in mental health outcomes per 1 °C increase in temperature, and under different heatwaves definitions. We further evaluated whether variables such as age, sex, socioeconomic status, and climate zone may explain the observed heterogeneity.

RESULTS

The keyword search yielded 4560 citations from which we identified 53 high temperatures/heatwaves studies that comprised over 1.7 million mental health-related mortality and 1.9 million morbidity cases in total. Our findings suggest associations between heat exposures and a range of mental health-related outcomes. Regarding high temperatures, our meta-analysis of study findings showed that for each 1 °C increase in temperature, the mental health-related mortality and morbidity increased with a RR of 1.022 (95%CI: 1.015-1.029) and 1.009 (95%CI: 1.007-1.015), respectively. The greatest mortality risk was attributed to substance-related mental disorders (RR, 1.046; 95%CI: 0.991-1.101), followed by organic mental disorders (RR, 1.033; 95%CI: 1.020-1.046). A 1 °C temperature rise was also associated with a significant increase in morbidity such as mood disorders, organic mental disorders, schizophrenia, neurotic and anxiety disorders. Findings suggest evidence of vulnerability for populations living in tropical and subtropical climate zones, and for people aged more than 65 years. There were significant moderate and high heterogeneities between effect estimates in overall mortality and morbidity categories, respectively. Lower heterogeneity was noted in some subgroups. The magnitude of the effect estimates for heatwaves varied depending on definitions used. The highest effect estimates for mental health-related morbidity was observed when heatwaves were defined as "mean temperature ≥90th percentile for ≥3 days" (RR, 1.753; 95%CI: 0.567-5.421), and a significant effect was also observed when the definition was "mean temperature ≥95th percentile for ≥3 days", with a RR of 1.064 (95%CI: 1.006-1.123).

CONCLUSIONS

Our findings support the hypothesis of a positive association between elevated ambient temperatures and/or heatwaves and adverse mental health outcomes. This problem will likely increase with a warming climate, especially in the context of climate change. Further high-quality studies are needed to identify modifying factors of heat impacts.

Unequal effects of climate change and pre-existing inequalities on the mental health of global populations

Climate change is already having unequal effects on the mental health of individuals and communities and will increasingly compound pre-existing mental health inequalities globally. Psychiatrists have a vital part to play in improving both awareness and scientific understanding of structural mechanisms that perpetuate these inequalities, and in responding to global calls for action to promote climate justice and resilience, which are central foundations for good mental and physical health.

Effect of extreme temperatures on daily emergency room visits for mental disorders

Relatively few studies investigated the effects of extreme temperatures (both heat and cold) on mental health (ICD-9: 290-319; ICD-10: F00-F99) and the potential effect modifications by individuals' age, sex, and race. We aimed to explore the effect of extreme temperatures of both heat and cold on the emergency room (ER) visits for mental health disorders, and conducted a stratified analysis to identify possible susceptible population in Erie and Niagara counties, NY, USA. To assess the short-term impacts of daily maximum temperature on ER visits related to mental disorders (2009-2015), we applied a quasi-Poisson generalized linear model combined with a distributed lag non-linear model (DLNM). The model was adjusted for day of the week, precipitation, long-term time trend, and seasonality. We found that there were positive associations between short-term exposure to extreme ambient temperatures and increased ER visits for mental disorders, and the effects can vary by individual factors. We found heat effect (relative risk (RR) = 1.16; 95% confidence intervals (CI), 1.06-1.27) on exacerbated mental disorders became intense in the study region and subgroup of population (the elderly) being more susceptible to extreme heat than any other age group. For extreme cold, we found that there is a substantial delay effect of 14 days (RR = 1.25; 95% CI = 1.08-1.45), which is particularly burdensome to the age group of 50-64 years old and African-Americans. Our findings suggest that there is a positive association between short-term exposure to extreme ambient temperature (heat and cold) and increased ER visits for mental disorders, and the effects vary as a function of individual factors, such as age and race.

Suicide and Associations with Air Pollution and Ambient Temperature: A Systematic Review and Meta-Analysis

Given health threats of climate change, a comprehensive review of the impacts of ambient temperature and ar pollution on suicide is needed. We performed systematic literature review and meta-analysis of suicide risks associated with short-term exposure to ambient temperature and air pollution. Pubmed, Scopus, and Web of Science were searched for English-language publications using relevant keywords. Observational studies assessing risks of daily suicide and suicide attempts associated with temperature, particulate matter with aerodynamic diameter ≤10 μm (PM₁₀) and ≤2.5 mm (PM_2.5), ozone (O₃), sulfur dioxide (SO₂), nitrogen dioxide (NO₂), and carbon monoxide (CO) were included. Data extraction was independently performed in duplicate. Random-effect meta-analysis was applied to pool risk ratios (RRs) for increases in daily suicide per interquartile range (IQR) increase in exposure. Meta-regression analysis was applied to examine effect modification by income level based on gross national income (GNI) per capita, national suicide rates, and average level of exposure factors. In total 2274 articles were screened, with 18 studies meeting inclusion criteria for air pollution and 32 studies for temperature. RRs of suicide per 7.1 °C temperature was 1.09 (95% CI: 1.06, 1.13). RRs of suicide per IQR increase in PM_2.5, PM₁₀, and NO₂ were 1.02 (95% CI: 1.00, 1.05), 1.01 (95% CI: 1.00, 1.03), and 1.03 (95% CI: 1.00, 1.07). O₃, SO₂, and CO were not associated with suicide. RR of suicide was significantly higher in higher-income than lower-income countries (1.09, 95% CI: 1.07, 1.11 and 1.20, 95% CI: 1.14, 1.26 per 7.1 °C increased temperature, respectively). Suicide risks associated with air pollution did not significantly differ by income level, national suicide rates, or average exposure levels. Research gaps were found for interactions between air pollution and temperature on suicide risks.

Climate “Psychopathology”

Abstract. Climate change is now widely recognized as the greatest threat faced by humanity for thousands of years and is known to affect the social and environmental determinants of health; including access to clean air, safe drinking water, sufficient food, and secure shelter ( WHO, 2018 ). Anthropogenic climate change has already resulted in warming and precipitation trends that claim 150,000 lives annually, and a recent report from the WHO forecasts that between 2030 and 2050 climate change will cause an additional 250,000 additional deaths per year ( WHO, 2018 ). The interaction between climate change, mental health, and physical health is not yet well understood. This review addresses the question of how climate change is affecting mental health and will demonstrate that climate psychopathologies really matter in the face of the climate emergency.

The effect of average temperature on suicide rates in five urban California counties, 1999-⁠2019: an ecological time series analysis

BACKGROUND

Suicide is among the top 10 leading causes of premature morality in the United States and its rates continue to increase. Thus, its prevention has become a salient public health responsibility. Risk factors of suicide transcend the individual and societal level as risk can increase based on climatic variables. The purpose of the present study is to evaluate the association between average temperature and suicide rates in the five most populous counties in California using mortality data from 1999 to 2019.

METHODS

Monthly counts of death by suicide for the five counties of interest were obtained from CDC WONDER. Monthly average, maximum, and minimum temperature were obtained from nCLIMDIV for the same time period. We modelled the association of each temperature variable with suicide rate using negative binomial generalized additive models accounting for the county-specific annual trend and monthly seasonality.

RESULTS

There were over 38,000 deaths by suicide in California's five most populous counties between 1999 and 2019. An increase in average temperature of 1 °C corresponded to a 0.82% increase in suicide rate (IRR = 1.0082 per °C; 95% CI = 1.0025-1.0140). Estimated coefficients for maximum temperature (IRR = 1.0069 per °C; 95% CI = 1.0021-1.0117) and minimum temperature (IRR = 1.0088 per °C; 95% CI = 1.0023-1.0153) were similar.

CONCLUSION

This study adds to a growing body of evidence supporting a causal effect of elevated temperature on suicide. Further investigation into environmental causes of suicide, as well as the biological and societal contexts mediating these relationships, is critical for the development and implementation of new public health interventions to reduce the incidence of suicide, particularly in the face increasing temperatures due to climate change.

Temporal patterns of suicide and circulatory system disease-related mortality are inversely correlated in several countries

BACKGROUND

Nearly 800,000 suicides occur worldwide annually and suicide rates are increasing faster than population growth. Unfortunately, the pathophysiology of suicide remains poorly understood, which has hindered suicide prevention efforts. However, mechanistic clues may be found by studying effects of seasonality on suicide and other mortality causes. Suicides tend to peak in spring-summer periods and nadir in fall-winter periods while circulatory system disease-related mortality tends to exhibit the opposite temporal trends. This study aimed to determine for the first time whether monthly temporal cross-correlations exist between suicide and circulatory system disease-related mortality at the population level. If so and if common biological factors moderate risks for both mortality types, such factors may be discoverable and utilized to improve suicide prevention.

METHODS

We conducted time series analyses of monthly mortality data from northern (England and Wales, South Korea, United States) and southern (Australia, Brazil) hemisphere countries during the period 2009-2018 (N = 41.8 million all-cause mortality cases). We used a Poisson regression variant of the standard cosinor model to determine peak months of mortality. We also estimated cross-correlations between monthly mortality counts from suicide and from circulatory system diseases.

RESULTS

Suicide and circulatory disease-related mortality temporal patterns were negatively correlated in Australia (- 0.32), Brazil (- 0.57), South Korea (- 0.32), and in the United States (- 0.66), but no temporal correlation was discernable in England and Wales.

CONCLUSIONS

The negative temporal cross-correlations between these mortality types we found in 4 of 5 countries studied suggest that seasonal factors broadly and inversely moderate risks for circulatory disease-related mortality and suicide, but not in all regions, indicating that the effect is not uniform. Since the seasonal factors of temperature and light exert opposite effects on suicide and circulatory disease-related mortality in several countries, we propose that physiologically-adaptive circulatory system responses to heat and light may increase risk for suicide and should be studied to determine whether they affect suicide risk. For example, heat and light increase production and release of the bioactive gas nitric oxide and reduce circulatory system disease by relaxing blood vessel tone, while elevated nitric oxide levels are associated with suicidal behavior, inverse effects that parallel the inverse temporal mortality patterns we detected.

The 2020 report of The Lancet Countdown on health and climate change: responding to converging crises

For the Chinese, French, German, and Spanish translations of the abstract see Supplementary Materials section.

Association between ambient temperature and injury by intentions and mechanisms: A case-crossover design with a distributed lag nonlinear model

Although injury is a leading cause of death worldwide, the association between ambient temperature and injury has received little research attention compared to the association of temperature with mortality and morbidity from non-external causes. With current climate change and increases in weather extremes, assessing the association between temperature and injury is important for determining public health priorities. Therefore, the present study examined the association between ambient temperature and injury risk with a focus on the intentions and mechanisms of injury. Using the national emergency database, we identified a total of 703,503 injured patients who had visited emergency departments in Seoul, South Korea from 2008 to 2016. We conducted a time-stratified case-crossover study using a conditional Poisson regression model, and applied a distributed lag nonlinear model to explore possible nonlinear and delayed effects of daily mean temperature on injury risk. Injury risk was significantly associated with ambient temperature, and temperature-injury association curves markedly differed with respect to intentions and mechanisms of injury. Although unintentional injuries increased significantly at both high and low temperatures, intentional injuries - including self-harm and assault - significantly increased only at high temperatures. The mechanism-specific analyses showed that injuries caused by traffic accidents and burns significantly increased at both high and low temperatures. However, injuries caused by all other mechanisms (i.e., fall, blunt object, machinery, penetration, and poisoning) significantly increased only at high temperatures, while injury due to slipping increased at low temperatures. Our study provides evidence that ambient temperature is associated with risk of injury, and this association differs depending on the intentions and mechanisms of injury. Overall, our findings help foster a more comprehensive understanding of the association between temperature and injury that can be used to establish appropriate public health policies and targeted interventions.

Effect of Extreme Weather Events on Mental Health: A Narrative Synthesis and Meta-Analysis for the UK

Extreme weather events are increasing in frequency and severity as a consequence of climate change and pose a significant threat to population mental health. This is the case even in temperate regions such as the United Kingdom (UK) where flooding and heat waves are forecast to become more common. We conducted a systematic review to quantify the prevalence and describe the causes of common mental health problems in populations exposed to extreme weather events in the UK. We searched Web of Science, EMBASE and PsycINFO for studies that measured the prevalence of depression, anxiety, and post-traumatic stress disorder (PTSD) in populations exposed to extreme weather events in the UK, published up to 12 December 2019. We included 17 studies, four of which were included in meta-analyses to determine the point prevalence of common mental health problems in the period within 12 months following extreme weather events. The point prevalence was 19.8% for anxiety (k = 4; n = 1458; 95% CI 7.42 to 32.15), 21.35% for depression (k = 4; n = 1458; 95% CI 9.04 to 33.65) and 30.36% for PTSD (k = 4; n = 1359; 95% CI 11.68 to 49.05). Key factors that affected mental ill health in people exposed to flooding were water depth and absence of flood warnings. Displacement from home underscored the narratives associated with people's perceptions of the impact of flooding. The high prevalence of common mental health problems suggests that the prevention of mental ill health in populations at risk or exposed to extreme weather events should be a UK public health priority.

Extremes in water availability and suicide: Evidence from a nationally representative sample of rural Indian adults

BACKGROUND

Extremes in water availability, either exceptionally wet or dry conditions, can damage crops and may detrimentally affect the livelihood and well-being of people engaged in agriculture. We estimated the effect of water availability on suicide in rural India, a context where the majority of households are dependent upon agriculture.

METHODS

We used data from a nationally representative sample of 8.5 million people who were monitored for causes of death from 2001 to 2013. Water availability was measured with high-resolution precipitation and temperature data (i.e., the Standardized Precipitation Evapotranspiration Index). We used a fixed effects approach that modeled changes in water availability within districts (n = 569) over time (n = 13 years) to estimate the impact on suicide deaths. We restricted our analysis to rural areas and to deaths occurring during the growing season (June-March) among adults aged 15 or older, and controlled for sex, age, region, and year. We used Poisson regression with standard errors clustered at the district level and total deaths as the offset.

RESULTS

There were 9456 suicides and 249,786 total deaths in our study population between 2001 and 2013. Compared to normal growing seasons, the percent of deaths due to suicide increased by 18.7% during extremely wet growing seasons (95% CI: 6.2, 31.2) and by 3.6% during extremely dry growing seasons (95% CI: -17.9, 25.0). We found that effects varied by age.

CONCLUSIONS

We found extremes is water availability associated with an increase in suicide. Abnormally wet growing conditions may play an important, yet overlooked, role in suicide among rural Indian adults.

Emergency department visits for panic attacks and ambient temperature: A time-stratified case-crossover analysis

BACKGROUND

Panic disorder is a common anxiety disorder affecting up to 5% of the population. Although its pathogenesis is unclear, evidence about its association with ambient temperature is limited. We aimed to investigate the association between short-term exposure to increased ambient temperature and exacerbation of panic attacks requiring emergency department visits.

METHODS

From the national emergency database of South Korea, we identified 1,926 patients who presented with panic attacks at the emergency department in Seoul from 2008 to 2014. Using a time-stratified case-crossover design and conditional logistic regression analysis, we compared ambient temperature levels on emergency department visits and correspondingly matched-control days.

RESULTS

Increased ambient temperature levels were significantly associated with panic attacks. The risk of a panic attack increased by 2.2% (95% confidence interval, 0.7-3.8%) per every 1°C increase in temperature. This association was significant after adjusting for air pollutants.

CONCLUSIONS

Our results provide new evidence that short-term exposure to increased ambient temperature may increase the risk of exacerbation of panic attacks. These findings may provide a basis for further research to establish the association between panic attacks and ambient temperature, thus establishing preventive measures for panic attacks.

Suicide and apparent temperature in the two capitals cities in the iberian peninsula

Different authors have identified geographic variations in the rates of suicide. This study aims to discuss the limitations of the officially recorded suicide data and to evaluate the statistical relationship between a biometeorological index, Apparent Temperature (AT), and suicide in Madrid and Lisbon. We performed a time-series study. The association was analyzed using a quasi-Poisson regression model. To assess potential delayed and non-linear effects of AT on suicides, a lag non-linear model was fitted in a generalized additive model. There was an average rate of 3.30 suicides/100,000 inhabitants in Madrid and of 7.92 suicides/100,000 inhabitants in Lisbon, and a downward trend was found throughout the period. In Madrid, there is no statistically significant association between AT and suicide. However, in Lisbon, under higher AT, there was a higher risk of suicide. The highest accumulated statistically significant Relative Risk (RR) of suicide was detected at 7 days after the exposure, when at 38 °C, the risk of suicide is 2.7 times that existing at the median AT, 20.62°. The average mortality rate recorded in Lisbon was 41.6% higher than that registered in Madrid. However, the limitations of suicide record databases in Spain and Portugal have to be taken into account when analyzing incidence and especially when comparing data from different countries. It is necessary to improve the filing systems of violent deaths in order to perform reliable epidemiological studies.

Global warming, heat-related illnesses, and the dermatologist

Global warming, provoked by the greenhouse effect of high levels of atmospheric gases (most notably carbon dioxide and methane), directly threatens human health and survival. Individuals vary in their capacity to tolerate episodes of extreme heat. Because skin is the organ tasked with heat dissipation, it is important for dermatologists to be versed in the physiology of cutaneous heat dissipation and cognizant of clinical settings in which the skin’s thermoregulatory responses may be impaired. When the external temperature is lower than that of the skin, the skin releases internal heat through direct thermal exchange with the environment, a process that is aided by an expansion of cutaneous blood flow and eccrine sweating. Cooling through the evaporation of sweat is effective even when the external temperature exceeds that of skin. Many factors, including environmental and physiological (e.g., age and sex), and pathological (e.g., preexisting illnesses, disorders of eccrine function, and medications) considerations, affect the skin’s capacity to thermoregulate. Identification of individuals at increased risk for heat-related morbidity and mortality will become increasingly important in the care of patients.

Nonlinear temperature-suicide association in Japan from 1972 to 2015: Its heterogeneity and the role of climate, demographic, and socioeconomic factors

It has been reported that suicide is associated with ambient temperature; however, the heterogeneity in this association and its underlying factors have not been extensively investigated. Therefore, we investigated the spatial and temporal variation in the temperature-suicide association and examined climatic, demographic, and socioeconomic factors that may underlie such heterogeneity. We analyzed the daily time-series data for the suicide counts and ambient temperature, which were collected for the 47 prefectures of Japan from 1972 to 2015, using a two-stage analysis. In the first stage, the prefecture-specific temperature-suicide association was estimated by using a generalized linear model. In the second stage, the prefecture-specific associations were pooled, and key factors explaining the spatial and temporal variation were identified by using mixed effects meta-regression. Results showed that there is an inverted J-shape nonlinear association between temperature and suicide; the suicide risk increased with temperature but leveled off above 24.4 °C. The nationwide relative risk (RR) for the maximum suicide temperature versus 5th temperature percentile (2.9 °C) was estimated as 1.26 (95% CI: 1.22, 1.29). The RRs were larger for females than for males (1.32 vs. 1.22) and larger for elderly people (≥65 y) than for the non-elderly (15-64 y) (1.51 vs. 1.18). The RRs were larger for rural prefectures, which are characterized by smaller population, higher proportions of females and elderly people, and lower levels of financial capability and the proportion of highly educated people. The RRs were also larger in colder and less humid prefectures. These findings may help in understanding the potential mechanism of the temperature-suicide association and projecting the future risk of suicide under climate change.

Short-term effect of apparent temperature on daily emergency visits for mental and behavioral disorders in Beijing, China: A time-series study

BACKGROUND

The relationship between temperature and mental disorders is still unclear. This study aims to assess the short-term effect of apparent temperature (AT) on daily emergency visits of mental and behavioral disorders (MDs) in Beijing, China.

METHODS

Daily counts of emergency visits related to MDs in Beijing from 2016 to 2018 were obtained. A quasi-Poisson generalized additive model combined with a distributed lag non-linear model (DLNM) was applied to analyze the lag-exposure-response relationship between AT and emergency admissions related to MDs. Sunshine duration, precipitation, PM_2.5, SO₂, O₃, time trend, day of week and holiday were adjusted in the model.

RESULTS

Total daily emergency visits for MDs during the study period were 16,606. With the reference of -2.4 °C (temperature with the minimum emergency visit risk), the single day effects of low AT (-8.6 °C, 10th percentile) and high AT (9.2 °C, 90th percentile) on MDs emergency visits reached a relative risk peak of 1.043 (95%CI: 1.017-1.069) on lag day 4 and 1.105 (95%CI: 1.006-1.215) on lag day 1, respectively. The greatest cumulative effect of high AT emerged on lag 0-5 days and reached a relative risk of 1.435 (95%CI: 1.048-1.965), while no significant cumulative effect of low AT was observed. There was a significant effect of high AT on emergency visits of MDs due to psychoactive substance use and male patients.

CONCLUSIONS

Both low and high AT are demonstrated to be the significant risk factors of MDs, which highlights the need of strengthening the health interventions, patient medical services and early warning for patients.

Hot Weather and Suicide Deaths among Older Adults in Hong Kong, 1976-2014: A Retrospective Study

Findings of the association between hot weather and suicide in a subtropical city such as Hong Kong are inconsistent. This study aimed to revisit the association by identifying meteorological risk factors for older-adult suicides in Hong Kong using a time-series approach. A retrospective study was conducted on older-adult (aged ≥65) suicide deaths in Hong Kong from 1976 to 2014. Suicides were classified into those involving violent methods and those involving nonviolent methods. Meteorological data, including ambient temperature, were retrieved. Transfer function time-series models were fitted. In total, 7314 older-adult suicide deaths involving violent methods and 630 involving nonviolent methods were recorded. For violent-method suicides, a monthly average daily minimum ambient temperature was determined to best predict the monthly rate, and a daily maximum ambient temperature of 30.3 °C was considered the threshold. For suicide deaths involving nonviolent methods, the number of days in a month for which the daily maximum ambient temperature exceeded 32.7 °C could best predict the monthly rate. Higher ambient temperature was associated with more older-adult suicide deaths, both from violent and nonviolent methods. Weather-focused preventive measures for older-adult suicides are necessary, such as the provision of more public air-conditioned areas where older adults can shelter from extreme hot weather.

Impact of meteorological parameters on suicide mortality rates: A case-crossover analysis in Southern Germany (1990-2006)

BACKGROUND

There is evidence for a seasonal pattern of suicides with peaks in spring and early summer; however, only a limited number of studies has investigated whether daily changes in meteorological variables may trigger suicides.

METHODS

Daily fatal suicide (N = 10,595) and meteorological data were available for four Bavarian cities and ten counties (Germany) for 1990-2006. City/county-specific immediate, delayed and cumulative effects of air temperature, sunshine duration, and cloud cover on suicides were analyzed using a time-stratified case-crossover approach; city/county-specific effects were then combined using random effects meta-analysis. Potential effect modifiers were specific weather conditions, personal or regional characteristics, and season.

RESULTS

A 5 °C increase in air temperature on the day before a suicide compared to the control days was associated with a 5.7% (95% confidence interval (CI): 0.6; 11.0) higher suicide risk. Further, the suicide risk was 6.5% (95% CI: 0.2; 13.3) higher on days with low/medium cloud cover (0-6 oktas) compared to days with high cloud cover (7-8 oktas). While daily changes in temperature were not associated with suicides in spring, we found a higher suicide risk in summer, autumn, and winter in association with temperature increases. The effects of cloud cover were strongest in summer and autumn and on days with temperature above the median (>8.8 °C). Sunshine duration was not associated with suicides.

CONCLUSION

We found a higher risk for suicides in association with short-term increases in air temperature on the day before the event compared to the control days and on days with low to medium cloud cover. This may highlight times when people are more likely to commit suicide.

What is the role of meteorological variables on involuntary admission in psychiatric ward? An Italian cross-sectional study

Weather affects physical and mental health through several modalities which are not fully elucidated. The aim of the present study was to investigate the impact of meteorological variables and other indexes in a large sample of hospitalized patients, focusing on subjects who were involuntarily admitted. We hypothesized a direct relation between the amount of involuntary admissions and mean sunshine hours. Furthermore, we supposed that specific meteorological factors may significantly influence hospitalizations of patients affected by severe psychiatric conditions. All subjects were consecutively recruited from the Psychiatric Inpatient Unit of San Luigi Gonzaga Hospital, Orbassano (Turin, Italy) from September 2013 to August 2015. Socio-demographic and clinical characteristics were carefully collected. Meteorological data were derived by the Italian Meteorology's Climate Data Service of Physics Department of the University of Turin (Latitude: 45°03'07,15″ Nord, Longitude: 007°40'53,30″ Est, Altitude: 254 m above the sea level) (http://www.meteo.dfg.unito.it/). Our data indicate significant differences regarding temperature (minimum, maximum, and medium), solar radiation, humidex and windchill index, and hours of sunshine in psychiatric patients who were involuntarily hospitalized. After logistic regression analyses, only maximum and medium temperature, and humidex index remained significantly associated with involuntary admission in an emergency psychiatric ward. The limitations of this study include the cross-sectional study design and the single hospital for patients' recruitment. Furthermore, results and seasonal patterns obtained by patients requiring hospitalization might significantly differ from those who were not hospitalized. Exploring in a more detailed manner those environmental factors associated with involuntary admissions could lead to early intervention and prevention strategies for such distressing hospitalizations.

Air Pollution (Particulate Matter) Exposure and Associations with Depression, Anxiety, Bipolar, Psychosis and Suicide Risk: A Systematic Review and Meta-Analysis

BACKGROUND

Particulate air pollution's physical health effects are well known, but associations between particulate matter (PM) exposure and mental illness have not yet been established. However, there is increasing interest in emerging evidence supporting a possible etiological link.

OBJECTIVES

This systematic review aims to provide a comprehensive overview and synthesis of the epidemiological literature to date by investigating quantitative associations between PM and multiple adverse mental health outcomes (depression, anxiety, bipolar disorder, psychosis, or suicide).

METHODS

We undertook a systematic review and meta-analysis. We searched Medline, PsycINFO, and EMBASE from January 1974 to September 2017 for English-language human observational studies reporting quantitative associations between exposure to PM < 1.0 μ m in aerodynamic diameter (ultrafine particles) and PM < 2.5 and < 10 μ m in aerodynamic diameter (PM 2.5 and PM 10 , respectively) and the above psychiatric outcomes. We extracted data, appraised study quality using a published quality assessment tool, summarized methodological approaches, and conducted meta-analyses where appropriate.

RESULTS

Of 1,826 citations identified, 22 met our overall inclusion criteria, and we included 9 in our primary meta-analyses. In our meta-analysis of associations between long-term (> 6   months ) PM 2.5 exposure and depression (n = 5 studies), the pooled odds ratio was 1.102 per 10 - μ g / m 3 PM 2.5 increase (95% CI: 1.023, 1.189; I 2 = 0.00 % ). Two of the included studies investigating associations between long-term PM 2.5 exposure and anxiety also reported statistically significant positive associations, and we found a statistically significant association between short-term PM 10 exposure and suicide in meta-analysis at a 0-2 d cumulative exposure lag.

DISCUSSION

Our findings support the hypothesis of an association between long-term PM 2.5 exposure and depression, as well as supporting hypotheses of possible associations between long-term PM 2.5 exposure and anxiety and between short-term PM 10 exposure and suicide. The limited literature and methodological challenges in this field, including heterogeneous outcome definitions, exposure assessment, and residual confounding, suggest further high-quality studies are warranted to investigate potentially causal associations between air pollution and poor mental health. https://doi.org/10.1289/EHP4595.

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.

Suicide and Ambient Temperature: A Multi-Country Multi-City Study

BACKGROUND

Previous literature suggests that higher ambient temperature may play a role in increasing the risk of suicide. However, no multi-country study has explored the shape of the association and the role of moderate and extreme heat across different locations.

OBJECTIVES

We examined the short-term temperature-suicide relationship using daily time-series data collected for 341 locations in 12 countries for periods ranging from 4 to 40 y.

METHODS

We conducted a two-stage meta-analysis. First, we performed location-specific time-stratified case-crossover analyses to examine the temperature-suicide association for each location. Then, we used a multivariate meta-regression to combine the location-specific lag-cumulative nonlinear associations across all locations and by country.

RESULTS

A total of 1,320,148 suicides were included in this study. Higher ambient temperature was associated with an increased risk of suicide in general, and we observed a nonlinear association (inverted J-shaped curve) with the highest risk at 27°C. The relative risk (RR) for the highest risk was 1.33 (95% CI: 1.30, 1.36) compared with the risk at the first percentile. Country-specific results showed that the nonlinear associations were more obvious in northeast Asia (Japan, South Korea, and Taiwan). The temperature with the highest risk of suicide ranged from the 87th to 88th percentiles in the northeast Asian countries, whereas this value was the 99th percentile in Western countries (Canada, Spain, Switzerland, the UK, and the United States) and South Africa, where nearly linear associations were estimated. The country-specific RRs ranged from 1.31 (95% CI: 1.19, 1.44) in the United States to 1.65 (95% CI: 1.40, 1.93) in Taiwan, excluding countries where the results were substantially uncertain.

DISCUSSION

Our findings showed that the risk of suicide increased with increasing ambient temperature in many countries, but to varying extents and not necessarily linearly. This temperature-suicide association should be interpreted cautiously, and further evidence of the relationship and modifying factors is needed. https://doi.org/10.1289/EHP4898.