Projecting the Suicide Burden of Climate Change in the United States

Association of ambient temperature with intentional self-harm and suicide death in Seoul: a case-crossover design with a distributed lag nonlinear model

Previous epidemiological studies have reported a short-term association between ambient temperature and suicide risk. To gain a clearer understanding of this association, it is essential to differentiate the risk factors for intentional self-harm (ISH) from those specifically associated with suicide deaths. Therefore, this study aims to examine whether the association between daily temperature and ISH or suicide deaths differs by age and sex. Between 2014 and 2019, cases of emergency room visits related to ISH and suicide deaths in Seoul were identified. A time-stratified case-crossover design was used to adjust for temporal trends and seasonal variation. A distributed lag nonlinear model was used to analyze the nonlinear and time-delayed effect of ambient temperature on ISH and suicide deaths. Positive associations were observed between temperature and both ISH and suicide deaths. For ISH, the relative risk (RR) was high at 1.17 (95% confidence interval (CI): 1.03, 1.34) for a temperature of 25.7 °C compared with 14.8 °C. The RR for suicide death was higher than those for ISH, at 1.43 (95% CI: 1.03, 2.00) for a temperature of 33.7 °C. These associations varied by age and sex, with males and females aged 35-64 years showing increased susceptibility to suicide deaths. This study provides detailed evidence that unusually high temperatures, both anomalous and out of season, may trigger suicidal behaviors, including both ISH and suicide deaths.

Changes in meteorological conditions as near-term risk factors for suicide attempts

To evaluate the impact of acute meteorological changes (i.e., maximum temperature, humidity, wind speed, atmospheric pressure, cloud coverage, visibility, precipitation) as situational risk factors proximal (i.e., present in the hours directly preceding) to suicide attempts. Participants were 578 adult patients who were hospitalized within 24 h of a suicide attempt at the only Level 1 trauma hospital in the state of Mississippi. Participants completed a semi-structured interview to determine home address and exact timing of their suicide attempt. A within-person, case-crossover design was used with each patient serving as their own control. Meteorological variables were generated for the 6-hours preceding each patient's suicide attempt (case period) and corresponding hours the day prior (control period). Conditional logistic regression analyses were used to examine predictors of suicide attempts, and biological sex and season were evaluated as potential moderators. The presence of precipitation was associated with reduced odds of suicide attempts. Wind speed was marginally positively associated with suicide attempts among males, and visibility was positively associated with suicide attempts among females. Maximum temperature was positively associated with suicide attempts in the spring. Wind speed, visibility, maximum temperature, and precipitation (absence of) may represent situational risk factors for suicide attempts. Future studies should evaluate additional near-term situational risk factors and determine how to leverage this information to improve suicide risk management efforts to ultimately ameliorate the burden of suicide.

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.

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.

Vulnerable, Resilient, or Both? A Qualitative Study of Adaptation Resources and Behaviors to Heat Waves and Health Outcomes of Low-Income Residents of Urban Heat Islands

Little is known of how low-income residents of urban heat islands engage their knowledge, attitudes, behaviors, and resources to mitigate the health impacts of heat waves. In this qualitative study, we conducted semi-structured interviews with 40 adults in two such neighborhoods in Los Angeles California to explore their adaptation resources and behaviors, the impacts of heat waves on physical and mental health, and threat assessments of future heat waves. Eighty percent of participants received advanced warning of heat waves from television news and social media. The most common resource was air conditioning (AC) units or fans. However, one-third of participants lacked AC, and many of those with AC engaged in limited use due primarily to the high cost of electricity. Adaptation behaviors include staying hydrated, remaining indoors or going to cooler locations, reducing energy usage, and consuming certain foods and drinks. Most of the participants reported some physical or mental health problem or symptom during heat waves, suggesting vulnerability to heat waves. Almost all participants asserted that heat waves were likely to increase in frequency and intensity with adverse health effects for vulnerable populations. Despite limited resources, low-income residents of urban heat islands utilize a wide range of behaviors to minimize the severity of health impacts, suggesting they are both vulnerable and resilient to heat waves.