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.

Few studies have explored the influence of socioeconomic status (SES) on the heat vulnerability of mental health (MH) patients. As individual socioeconomic data was unavailable, we aimed to fill this gap by using the healthcare system type as a proxy for SES. Brazilian national statistics indicate that public patients have lower SES than private. Therefore, we compared the risk of emergency department visits (EDVs) for MH between patients from both healthcare types. EDVs for MH disorders from all nine public (101,452 visits) and one large private facility (154,954) in Curitiba were assessed (2017-2021). Daily mean temperature was gathered and weighed from 3 stations. Distributed-lag non-linear model with quasi-Poisson (maximum 10-lags) was used to assess the risk. We stratified by private and public, age, and gender under moderate and extreme heat. Additionally, we calculated the attributable fraction (AF), which translates individual risks into population-representative burdens - especially useful for public policies. Random-effects meta-regression pooled the risk estimates between healthcare systems. Public patients showed significant risks immediately as temperatures started to increase. Their cumulative relative risk (RR) of MH-EDV was 7.5 % higher than the private patients (Q-Test 26.2 %) under moderate heat, suggesting their particular heat vulnerability. Differently, private patients showed significant risks only under extreme heat, when their RR became 4.3 % higher than public (Q-Test 6.2 %). These findings suggest that private patients have a relatively greater adaptation capacity to heat. However, when faced with extreme heat, their current adaptation means were potentially insufficient, so they needed and could access healthcare freely, unlike their public counterparts. MH patients would benefit from measures to reduce heat vulnerability and access barriers, increasing equity between the healthcare systems in Brazil. AF of EDVs due to extreme heat was 0.33 % (95%CI 0.16;0.50) for the total sample (859 EDVs). This corroborates that such broad population-level policies are urgently needed as climate change progresses.

Objectives: Quantify the risk of mental health (MH)-related emergency department visits (EDVs) due to heat, in the city of Curitiba, Brazil. Design: Daily time series analysis, using quasi-Poisson combined with distributed lag non-linear model on EDV for MH disorders, from 2017 to 2021. Setting: All nine emergency centres from the public health system, in Curitiba. Participants: 101 452 EDVs for MH disorders and suicide attempts over 5 years, from patients residing inside the territory of Curitiba. Main outcome measure: Relative risk of EDV (RR _EDV ) due to extreme mean temperature (24.5°C, 99th percentile) relative to the median (18.02°C), controlling for long-term trends, air pollution and humidity, and measuring effects delayed up to 10 days. Results: Extreme heat was associated with higher single-lag EDV risk of RR _EDV 1.03(95% CI 1.01 to 1.05—single-lag 2), and cumulatively of RR _EDV 1.15 (95% CI 1.05 to 1.26—lag-cumulative 0–6). Strong risk was observed for patients with suicide attempts (RR _EDV 1.85, 95% CI 1.08 to 3.16) and neurotic disorders (RR _EDV 1.18, 95% CI 1.06 to 1.31). As to demographic subgroups, females (RR _EDV 1.20, 95% CI 1.08 to 1.34) and patients aged 18–64 (RR _EDV 1.18, 95% CI 1.07 to 1.30) were significantly endangered. Extreme heat resulted in lower risks of EDV for patients with organic disorders (RR _EDV 0.60, 95% CI 0.40 to 0.89), personality disorders (RR _EDV 0.48, 95% CI 0.26 to 0.91) and MH in general in the elderly ≥65 (RR _EDV 0.77, 95% CI 0.60 to 0.98). We found no significant RR _EDV among males and patients aged 0–17. Conclusion: The risk of MH-related EDV due to heat is elevated for the entire study population, but very differentiated by subgroups. This opens avenue for adaptation policies in healthcare: such as monitoring populations at risk and establishing an early warning systems to prevent exacerbation of MH episodes and to reduce suicide attempts. Further studies are welcome, why the reported risk differences occur and what, if any, role healthcare seeking barriers might play.

While recent studies have advanced our understanding of how heat affects mental health, the underlying mechanisms of this relationship remain fragmented. Previous reviews have emphasized broad and general physiological, psychological, behavioural, and social pathways, often neglecting the heterogeneity of mental disorders in terms of vulnerability and outcomes. We conducted a narrative review to tackle this gap and propose an outcome-oriented framework to better integrate evidence on heat-related mental health risks. We searched PubMed and Google Scholar from January 2023 to September 2025 and conducted backward citation tracking of relevant reviews and primary studies, with no restrictions on publication language, date, or article type. The review focuses on two distinct yet interrelated pathophysiological-related outcomes: (1) exacerbation of pre-existing mental health disorders, and (2) heat-related illnesses such as heat exhaustion and heat stroke. Moreover, we integrated these pathways to six psychiatric conditions most established as heat sensitive: organic disorders (International Classification of Diseases-10 ^th Edition F00-F09), substance misuse (F10-F19), schizophrenia (F20-F29), bipolar disorders (F31), neurotic disorders (F40-F49), and suicidal behaviour (X60-X84). First, our findings show that heat exposure can exacerbate symptoms in individuals with schizophrenia, bipolar disorder, anxiety disorders, and suicidal behaviour. Key mechanisms include (i) neurotransmitter imbalances, (ii) physiological stress, and (iii) sleep disruption. Second, heat exposure can contribute to heat-related illnesses, particularly among individuals with organic disorders, substance misuse, schizophrenia, and bipolar disorder due to (i) ineffective thermoregulatory behaviours, (ii) impaired neuropathways, and (iii) interactions with psychotropic medications or substances. By mapping outcome- and diagnosis-specific pathways, this review offers a more integrated understanding of how heat impacts mental health. This approach may help clinicians anticipate exacerbations and guide tailored interventions. It also provides a conceptual basis for future, precise, mechanism-driven research questions and for policymakers to design targeted adaptation strategies in public health.

Central Asia is among the regions most affected by climate change hazards. However, there is a significant gap in the literature regarding the health impacts of climate change in this region, which hinders the development of local policies. The existing publications largely consist of essays and opinion articles, often lacking scientific rigor and failing to analyze the current health impacts of climate change using local and primary data. To update the state of peer-reviewed literature and assess the current impact of climate change on human health in Central Asia, we conducted a rapid review of English- and Russian-language peer-reviewed studies. We searched PubMed, Google Scholar, and eLIBRARY.RU for literature on the nexus between climate change and health in the five Central Asian countries, covering publications from 2000 to 2025. The findings reinforce concerns raised in previous reviews—that research in this field remains alarmingly underdeveloped. From the limited peer-reviewed studies available—six in English and seven in Russian—we found that the main climate-related exposures examined in the region include heat and heatwaves, air pollution, melting glaciers, changes in rainfall patterns, and floods. Likewise, the most frequently analyzed health outcomes are cardiovascular and respiratory diseases, communicable diseases, and nutritional disorders. Given the scarcity of primary research on the health impacts of climate change in Central Asia, we inferred these impacts by considering (i) the most common climate hazards and (ii) the most prevalent climate-sensitive diseases in the region. In this context, it is reasonable to suppose that climate change has the potential to impact a wide range of health conditions, including cardiovascular, respiratory, mental health, neurological, genitourinary, infectious, nutritional, maternal/neonatal, allergic, and endocrine disorders. Despite these pressing concerns, research on Central Asia remains largely overlooked by the global public health and medical community. Fostering the climate and health discourse in the region is essential to advance public health under a warming climate, with the ultimate goal of promoting health and preventing further morbidity and mortality locally.

Attributing health outcomes to climate-related exposures is essential for informing adaptive policy, yet Southeast Asia, one of the world's most climate-vulnerable regions, remains critically underrepresented in attribution research. To address this gap, we conducted a scoping review of studies linking climate exposures to health burdens in the region. Although growing evidence demonstrates substantial health impacts from air pollution, heat, and extreme weather, the regional research landscape remains critically imbalanced, marked by neglect of other major hazards-including floods, droughts, extreme rainfall, storms and sea-level rise-and substantial methodological fragmentation. From 5294 records screened, 77 studies met our inclusion criteria. The evidence is dominated by air pollution research, the focus of 70% of studies and linked to up to 31% of all-cause mortality and an estimated 296,000 annual deaths from wildfire smoke during El Niño events. Heat, the second most studied exposure, was associated with up to 8.61% of mortality in Bangkok. In contrast, extreme events such as heatwaves, floods and storms were least frequently investigated. These findings reveal a critical misalignment between regional climate risks and current research focus. Standardized attribution frameworks are urgently needed to support integrated climate-health modeling and guide equitable, evidence-based adaptation across Southeast Asia.