The impact of climate change on mental health (but will mental health be discussed at Copenhagen?)

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.

Residential greenness for mitigating impacts of extreme heat events on depression and supporting mental health

Background

Residential green spaces (RGS) are a crucial aspect of urban life, which provide residents with a positive living environment both for mental and physical well-being. However, extreme heat events caused by global warming and local urban heat island effects are threatening the public health of rapidly growing populations. This is especially true for mental health. Depression is a mental illness that can be impacted by extreme heat events, i.e., heatwaves.

Objective

This study aimed to investigate the potential for residential green spaces (RGS) to alleviate depression by reducing heat stress sensitivity during extreme heat events.

Methods

We conducted a literature review using scientometric analysis with CiteSpace to summarize existing research on the relationships between RGS, depression, and heatwaves. We proposed a conceptual framework for the relationship between RGS and depression, and that extreme heat events may be an important contributor to depression.

Results

Our review found that RGS can provide ecosystem services that lower ambient temperatures through evaporative cooling, radiation reflection, humidity regulation, and shading. Different types of RGS, i.e., small green spaces, green roofs, green walls, and street trees, have varying cooling capacities. The mechanisms by which RGS alleviate depression during heatwaves involve green space composition, exposure, physical activity, social contacts, and cohesion. And we proposed a conceptual framework for the relationship between RGS and depression, and that extreme heat events may be an important contributor to depression.

Conclusion

We present a multidimensional RGS evaluation roadmap to inform green space design for reducing depression during heatwaves. Establishing RGS multidimensional evaluation can guide future research on leveraging RGS to build resilience against extreme heat and improve public mental health.

Short-term exposure to temperature and mental health in North Carolina: a distributed lag nonlinear analysis

Adverse mental health outcomes have been associated with high temperatures in studies worldwide. Few studies explore a broad range of mental health outcomes, and to our knowledge, none are specific to NC, USA. This ecological study explored the relationship between ambient temperature and mental health outcomes (suicide, self-harm and suicide ideation, anxiety and stress, mood disorders, and depression) in six urban counties across the state of NC, USA. We applied a quasi-Poisson generalized linear model combined with a distributed lag nonlinear model (DLNM) to examine the short-term effects of daily ambient temperature on emergency admissions for mental health conditions (2016 to 2018) and violent deaths (2004 to 2018). The results were predominately insignificant, with some key exceptions. The county with the greatest temperature range (Wake) displays higher levels of significance, while counties with the lowest temperature ranges (New Hanover and Pitt) are almost entirely insignificant. Self-harm and suicidal ideation peak in the warm months (July) and generally exhibit a protective effect at lower temperatures and shorter lag intervals. Whereas anxiety, depression, and major depressive disorders peak in the cooler months (May and September). Suicide is the only outcome that favored a 20-day lag period in the sensitivity analysis, although the association with temperature was insignificant. Our findings suggest additional research is needed across a suite of mental health outcomes to fully understand the effects of temperatures on mental health.

Stressors related to the Covid-19 pandemic, climate change, and the Ukraine crisis, and their impact on stress symptoms in Germany: analysis of cross-sectional survey data

BACKGROUND

Climate change, the Covid-19 pandemic, and the Ukraine crisis are considered unprecedented global stressors, potentially associated with serious health consequences. However, simultaneous effects of these stressors are not yet understood, making it difficult to evaluate their relative contribution to the population burden and potential future manifestations in clinically significant psychiatric disorders. This study aimed at disentangling the relative contribution of the three stressor groups on current sub-clinical stress symptoms.

METHODS

A cross-sectional, representative survey study was conducted two months after the outbreak of the Ukraine war in Germany. Proportional quota sampling was applied for age, gender, income, and regional characteristics. Data were recruited by means of an online survey. 3094 data sets (1560 females) were included. Age ranged from 18-89 (M: 50.4 years; SD: 17.2). The Subclinical Stress Questionnaire (SSQ-25) served as main outcome measure. In collaboration with a professional media agency, 20 items were generated to capture salient population stressors. A three-factor exploratory structural equation model confirmed the appropriateness of this scale.

RESULTS

(1) Differences in subjective rankings revealed that stressors related to the Ukraine crisis were rated as most worrying, followed by climate change, and the Covid-19 pandemic (Generalized-Linear-Model: Epsilon = .97; F(1.94, 6001.14) = 1026.12, p < .001; η_p² = .25). (2) In a linear regression model (R² = .39), Covid-19 pandemic stressors were the only meaningful predictors for current ill-health (standardized β = .48). Ukraine crisis did not predict stress symptom profiles in the present sample. (3) Older and male individuals report less and/or less severe stress symptoms, although effect sizes were small (range: η² .11-.21). An older age also reduced the impact of Covid-19 stressors.

CONCLUSIONS

Researchers from the health sciences must consider overlapping effects from population stressors. Although the Ukraine crisis and climate change mark salient stressors, including economic threats, the Covid-19 pandemic still has a profound effect on ill-health and must be considered as a relevant factor in future manifestations of psychiatric and associated health consequences.

The Impact of Climate Change on Mental Health and Emotional Wellbeing: A Narrative Review of Current Evidence, and its Implications

Converging global evidence highlights the dire consequences of climate change for human mental health and wellbeing. This paper summarises literature across relevant disciplines to provide a comprehensive narrative review of the multiple pathways through which climate change interacts with mental health and wellbeing. Climate change acts as a risk amplifier by disrupting the conditions known to support good mental health, including socioeconomic, cultural and environmental conditions, and living and working conditions. The disruptive influence of rising global temperatures and extreme weather events, such as experiencing a heatwave or water insecurity, compounds existing stressors experienced by individuals and communities. This has deleterious effects on people's mental health and is particularly acute for those groups already disadvantaged within and across countries. Awareness and experiences of escalating climate threats and climate inaction can generate understandable psychological distress; though strong emotional responses can also motivate climate action. We highlight opportunities to support individuals and communities to cope with and act on climate change. Consideration of the multiple and interconnected pathways of climate impacts and their influence on mental health determinants must inform evidence-based interventions. Appropriate action that centres climate justice can reduce the current and future mental health burden, while simultaneously improving the conditions that nurture wellbeing and equality. The presented evidence adds further weight to the need for decisive climate action by decision makers across all scales.

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.

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.

Anxiety and resilience in the face of natural disasters associated with climate change: A review and methodological critique

In the past two decades, climate change-related natural disasters, such as hurricanes, floods, and droughts have become increasingly frequent and severe, impacting the emotional and psychological well-being of those who are directly or indirectly exposed to them. Despite great interest in understanding differences in anxiety and resilience in response to natural disasters, enthusiasm appears to outstrip empirical clarity, as there remains considerable ambiguity as to determinants of resilient or pathological outcomes following exposure to natural disasters. In addition, there are several major methodological limitations in climate change and related natural disaster research, including the use of univariate analyses, cross-sectional design, and retrospective measures. Keeping these limitations in mind, we first review literature examining the mental health outcomes of natural disasters. Findings suggest that, overall, resilience is more common than pathological outcomes. Second, we use a multi-dimensional framework of resilience to selectively review factors at the event, individual, as well as family and community levels that could help inform resilient or pathological outcomes. Finally, we consider key limitations and future directions for research and practice in the field of anxiety and resilience in response to climate disasters.

The effect of PM2.5 exposure and risk perception on the mental stress of Nanjing citizens in China

The multidimensional characteristics and temporal dynamics of environmental risks have stimulated a social-scientific approach towards air pollution issues in recent decades. It's now widely acknowledged that air pollution has an ineligible influence on the psychological wellbeing of citizens beyond its well-established physical impact. We explored how fine particulate matter (PM_2.5), an essential air pollutant associated with morbidity and mortality, interacted with aspects of risk perception to influence citizen's mental stress level. Questionnaire data from 508 Nanjing citizens in China were collected across four seasons within an 18-month period. We found no evidence that mental stress was directly influenced by real-time PM_2.5 exposure. However, path analysis revealed that mental stress was subjected to the indirect influence of physical symptoms (β = 0.076, p = 0.11), by increasing perceived effect on health and increasing attribution to indoor pollution sources (β = 0.038, p = 0.005). Indoor attribution of PM_2.5 pollution was associated with perceived familiarity with risk (β = -0.095, p = 0.033), whereas outdoor attribution was associated with perceived control of risk (β = 0.091, p = 0.041). Public risk acceptable rate (PRAR) decreased as PM_2.5 concentration increased. In females, but not males, greater trust for government was associated with the increased acceptance of PM_2.5 (Year₂₀₁₇: β = -0.19, p = 0.003; Year₂₀₂₂: β = -0.21, p < 0.001). Using psychological statistical methods, our study implied that air pollution has a substantial association with psychological wellbeing in various ways, which might provide some references for public healthcare and risk communication.

Diverse and Complex Challenges to Migrant and Refugee Mental Health: Reflections of the M8 Alliance Expert Group on Migrant Health

Forced migration is likely to continue to grow in the coming years due to climate change, disease outbreaks, conflict, and other factors. There are a huge number of challenges to maintaining good health, and specifically good mental health, among migrants at all stages of migration. It is vital to fully understand these diverse challenges so that we can work towards overcoming them. In 2017, as a response to the growing health challenges faced by migrants and refugees, the M8 Alliance created an expert group focussing on migrant and refugee health. The group meets annually at the Sapienza University of Rome, Italy, and this article is based on the discussions that took place at the third annual meeting (6–7 June 2019) and a special session on “Protecting the Mental Health of Refugees and Migrants,” which took place on 27 October at the World Health Summit 2019 in Berlin. Our discussions are also supported by supplementary literature to present the diverse and complex challenges to the mental health of migrants and refugees. We conclude with some lessons learned and hope for the future.

Crisis support-seeking behavior and temperature in the United States: Is there an association in young adults and adolescents?

BACKGROUND

Mounting evidence demonstrates the relationship between high temperatures and adverse mental health outcomes. Yet, no study has examined the influence of temperature on crisis support-seeking behavior among youth in large urban areas.

METHODS

Crisis Text Line (CTL) is a text messaging service that provides crisis interventions for support-seeking individuals for a range of mental-health outcomes in the United States. We applied a distributed lag non-linear modeling technique to assess the short-term impacts of daily maximum and minimum temperature on crisis-related events in four metropolitan locations in the USA.

RESULTS

There were multiple positive associations in three of the four study locations that demonstrate crisis help-seeking behavior increased during anomalously warm conditions.

CONCLUSIONS

This study suggests that there is a significant association between high minimum or maximum temperatures and crisis help-seeking behaviors in young adults and adolescents in urban areas in the United States.

Influence of Heat Waves on Daily Hospital Visits for Mental Illness in Jinan, China-A Case-Crossover Study

Background: Given that more frequent and intensive extreme heat events have been projected based on climate change modeling, it is of significance to have a better understanding of the association between heat waves and mental illnesses. This study aimed to explore the effects of heat waves on daily hospital visits for mental illness in the summer of 2010 in Jinan, China. Methods: A symmetric bidirectional case-crossover study was firstly conducted to determine the relationship between daily hospital visits for mental illness and heat waves in Jinan in 2010. Multifactor logistic regression analysis was then used to analyze the influencing factors for daily hospital visits for mental illness during the heat wave periods. Results: Multivariable analysis showed that the heat wave events were associated with an increased risk of mental illness. The largest odds ratios (ORs) of the heat waves for daily hospital visits for mental illness were 2.231 (95% confidence interval (CI): 1.436–3.466) at a 3-day lag, 2.836 (95% CI: 1.776–4.525) at a 2-day lag, 3.178 (95% CI: 1.995–5.064) at a 3-day lag, and 2.988 (95% CI: 2.158–4.140) at a 2-day lag for the first, second, third, and fourth heat waves, respectively. The elderly, urban residents, outdoor workers, and singles may be high-risk populations for developing heat wave-related mental illness. Conclusions: Our study has supported that there is a positive association between heat waves and hospital visits for mental illness in the study site. Age, home address, occupation, and marital status were associated with daily hospital visits for mental illness during the heat wave periods.

Public Health Adaptation to Climate Change in OECD Countries

Climate change is a major challenge facing public health. National governments play a key role in public health adaptation to climate change, but there are competing views on what responsibilities and obligations this will—or should—include in different nations. This study aims to: (1) examine how national-level public health adaptation is occurring in Organization for Economic Cooperation and Development (OECD) countries; (2) examine the roles national governments are taking in public health adaptation; and (3) critically appraise three key governance dimensions of national-level health adaptation—cross-sectoral collaboration, vertical coordination and national health adaptation planning—and identify practical examples suited to different contexts. We systematically reviewed publicly available public health adaptation to climate change documents and webpages by national governments in ten OECD countries using systematic web searches, assessment of self-reporting, and content analysis. Our findings suggest national governments are primarily addressing infectious disease and heat-related risks posed by climate change, typically emphasizing capacity building or information-based groundwork initiatives. We find national governments are taking a variety of approaches to public health adaptation to climate change that do not follow expected convergence and divergence by governance structure. We discuss practical options for incorporating cross-sectoral collaboration, vertical coordination and national health adaptation planning into a variety of contexts and identify leaders national governments can look to to inform their public health adaptation planning. Following the adoption of the Paris Agreement and subsequent increased momentum for adaptation, research tracking adaptation is needed to define what health adaptation looks like in practice, reveal insights that can be taken up across states and sectors, and ensure policy orientated learning.

Heatwaves and Hospital Admissions for Mental Disorders in Northern Vietnam

Studies in high-income countries have shown an association between heatwaves and hospital admissions for mental disorders. It is unknown whether such associations exist in subtropical nations like Vietnam. The study aim was to investigate whether hospital admissions for mental disorders may be triggered, or exacerbated, by heat exposure and heatwaves, in a low- and middle-income country, Vietnam. For this, we used data from the Hanoi Mental Hospital over five years (2008–2012) to estimate the effect of heatwaves on admissions for mental disorders. A zero-inflated negative binomial regression model accounting for seasonality, time trend, days of week, and mean humidity was used to analyse the relationship. Heatwave events were mainly studied as periods of three or seven consecutive days above the threshold of 35°C daily maximum temperature (90^th percentile). The study result showed heatwaves increased the risk for admission in the whole group of mental disorders (F00-79) for more persistent heatwaves of at least 3 days when compared with non-heatwave periods. The relative risks were estimated at 1.04 (0.95–1.13), 1.15 (1.005–1.31), and 1.36 (1–1.90) for a one-, three- and seven-day heatwave, respectively. Admissions for mental disorders increased among men, residents in rural communities, and the elderly population during heatwaves. The groups of organic mental disorders, including symptomatic illnesses (F0-9) and mental retardation (F70-79), had increased admissions during heatwaves. The findings are novel in their focus on heatwave impact on mental diseases in a population habituating in a subtropical low- and middle-income country characterized by rapid epidemiological transitions and environmental changes.

Climate change: the next challenge for public mental health?

Climate change is increasingly recognized as one of the greatest threats to human health of the 21st century, with consequences that mental health professionals are also likely to face. While physical health impacts have been increasingly emphasized in literature and practice, recent scholarly literature indicates that climate change and related weather events and environmental changes can profoundly impact psychological well-being and mental health through both direct and indirect pathways, particularly among those with pre-existing vulnerabilities or those living in ecologically sensitive areas. Although knowledge is still limited about the connections between climate change and mental health, evidence is indicating that impacts may be felt at both the individual and community levels, with mental health outcomes ranging from psychological distress, depression and anxiety, to increased addictions and suicide rates. Drawing on examples from diverse geographical areas, this article highlights some climate-sensitive impacts that may be encountered by mental health professionals. We then suggest potential avenues for public mental health in light of current and projected changes, in order to stimulate thought, debate, and action.

A review of the consequences of global climate change on human health

The impact of climate change has been significant enough to endanger human health both directly and indirectly via heat stress, degraded air quality, rising sea levels, food and water security, extreme weather events (e.g., floods, droughts, earthquakes, volcano eruptions, tsunamis, hurricanes, etc.), vulnerable shelter, and population migration. The deterioration of environmental conditions may facilitate the transmission of diarrhea, vector-borne and infectious diseases, cardiovascular and respiratory illnesses, malnutrition, etc. Indirect effects of climate change such as mental health problems due to stress, loss of homes, economic instability, and forced migration are also unignorably important. Children, the elderly, and communities living in poverty are among the most vulnerable of the harmful effects due to climate change. In this article, we have reviewed the scientific evidence for the human health impact of climate change and analyzed the various diseases in association with changes in the atmospheric environment and climate conditions.

"My worries are rational, climate change is not": habitual ecological worrying is an adaptive response

Qualifications such as “global warming hysteria” and “energy policy schizophrenia” put forward by some climate change skeptics, usually outside the academic arena, may suggest that people who seriously worry about the environment suffer from psychological imbalance. The present study aimed to refute this thesis. While habitual worrying in general is strongly associated with psychopathological symptoms, in a survey a near-zero correlation was found between habitual ecological worrying and pathological worry. Instead, habitual ecological worrying was associated with pro-environmental attitudes and behaviors, and with a personality structure characterized by imagination and an appreciation for new ideas. The study had sufficient statistical power and measures were valid and reliable. The results confirm that those who habitually worry about the ecology are not only lacking in any psychopathology, but demonstrate a constructive and adaptive response to a serious problem. In the public domain, these findings may contribute to a more rational and less emotional debate on climate change and to the prevention of stigmatization of people who are genuinely concerned about our habitat and are prepared to do something about it (“habitual worriers are not crazy”). In the academic arena this study may contribute to environmental psychology (“habitual worrying is part of a green identity”), as well as to the literature on worry and anxiety (“habitual worrying can be a constructive response”).

Extreme Weather Events and Mental Health: Tackling the Psychosocial Challenge

Climate change is an emerging challenge to the mental health of entire humanity. Several studies, in recent times, have brought to light the adverse public mental health outcomes of extreme weather events for the suffering communities. The general public and the policy making bodies need to gain awareness about these impacts. Through such awareness, communities and their governments can institutionalize mechanisms to provide psychological support to the populations affected by climate change, before it becomes a massive public health challenge and starts affecting the social and vocational lives of people. There is an urgent need for addressing these impacts. The aim of this paper is to provide an overview of the deleterious effects of climate change related extreme weather events on mental health, the worldwide response of several communities to such events, and preparedness of the public and government to deal with these adverse mental health impacts. Policy imperatives to prevent and mitigate these impacts have been suggested. It is hoped that the psychologists, governments, and communities will act earnestly to prevent the impending harm to human mental health due to climate change.

The Psychological Impact of Exposure to the 2008 Snowstorms on Migrant Workers in China

This study aimed to estimate the prevalence of posttraumatic stress disorder (PTSD) and to identify associated risk factors among migrant workers 4 years after the 2008 snowstorm in China. A cross-sectional survey of 528 respondents was conducted to collect data in Changsha, the capital of Hunan Province. A multistage cluster sampling method was applied in selecting subjects from migrant workers’ gathering areas. Association between the independent variables and PTSD was analyzed using logistic regression analysis. The prevalence of PTSD was 17.42% among migrant workers in Changsha. Being male, being older than 35 years, being an electrician, having dependent children, suffering property damage, being without medical insurance, and having low social support were risk factors significantly related to the development of PTSD. Effective and sustainable mental health services should be directed particularly to the migrant workers, who are among the groups most vulnerable to the direct impact of snowstorms.

Temperature-related deaths in people with psychosis, dementia and substance misuse

BACKGROUND

Climate change is expected to have significant effects on human health, partly through an increase in extreme events such as heatwaves. People with mental illness may be at particular risk.

AIMS

To estimate risk conferred by high ambient temperature on patients with psychosis, dementia and substance misuse.

METHOD

We applied time-series regression analysis to data from a nationally representative primary care cohort study. Relative risk of death per 1°C increase in temperature was calculated above a threshold.

RESULTS

Patients with mental illness showed an overall increase in risk of death of 4.9% (95% CI 2.0-7.8) per 1°C increase in temperature above the 93rd percentile of the annual temperature distribution. Younger patients and those with a primary diagnosis of substance misuse demonstrated greatest mortality risk.

CONCLUSIONS

The increased risk of death during hot weather in patients with psychosis, dementia and substance misuse has implications for public health strategies during heatwaves.