Abstract
The One Health approach recognizes the interdependence of human, animal, and environmental health but has focused on zoonotic diseases and ecological disruption, with comparatively little attention to mental health. This article examines links among environmental change, zoonotic disease dynamics, human–animal relationships, and mental health and proposes a framework for integrating mental health into One Health. A structured search of literature published from 2010 to 2025 was conducted using PubMed, Scopus, and Google Scholar. Evidence indicates that environmental disruption, zoonotic outbreaks, and human–animal interactions affect mental health through overlapping pathways. Climate change and ecological degradation are associated with anxiety, trauma, and livelihood-related distress; zoonotic events may contribute through fear, stigma, social disruption, and economic insecurity; and human–animal relationships may have protective and adverse effects. These findings support a three-pathway model that may strengthen surveillance, preparedness, and policy responses while promoting more preventive and equitable approaches to health.
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Keywords: Climate change; Global health; Mental health; One Health; Zoonoses
Introduction
The One Health approach emphasizes the interdependence of human, animal, and environmental health and has become a central framework in global health. Its influence has been strongest in work on zoonotic diseases, antimicrobial resistance, and ecological disruption [
1–
3].
Global organizations, including the World Health Organization, Food and Agriculture Organization, World Organisation for Animal Health, and United Nations Environment Programme, have endorsed One Health frameworks to promote multisectoral collaboration [
1,
2]. Yet these frameworks have generally centered on infectious disease control and environmental risks, leaving mental health comparatively peripheral.
Mental disorders are major contributors to the global burden of disease and account for a substantial proportion of disability-adjusted life years worldwide. Mental health is also essential for achieving several Sustainable Development Goals, including those related to health, poverty reduction, and well-being. Even so, it remains insufficiently incorporated into interdisciplinary frameworks such as One Health.
Evidence increasingly links environmental change, biodiversity loss, and zoonotic disease outbreaks with adverse psychological outcomes [
4–
10]. Nevertheless, One Health discourse has not fully incorporated mental health.
Historically, One Health has been shaped by the priorities of infectious disease control, zoonotic spillover prevention, and environmental protection. Mental health has therefore often been treated as secondary, partly because psychological outcomes are less immediately visible, more difficult to measure across systems, and less prominent in traditional biomedical models. As ecological disruption, climate-related disasters, and research on human–animal–environment interactions have expanded, the psychological consequences of these systems have become harder to overlook. This shift supports a broader One Health model that integrates mental health to address both direct and indirect health outcomes and to support broader global health goals.
This article argues that mental health should be treated as a core component of One Health and proposes a conceptual framework to guide its integration. Rather than describing isolated associations, the article presents a pathway-based model that positions mental health as a cross-cutting and operational concern in One Health systems.
Methods
This viewpoint synthesizes interdisciplinary literature on mental health in the context of One Health. A structured search was conducted in PubMed, Scopus, and Google Scholar for articles published between January 2010 and March 2025.
Search terms included combinations of “One Health,” “mental health,” “climate change,” “eco-anxiety,” “zoonotic diseases,” “environmental determinants of mental health,” and “human–animal interaction.” Boolean operators (AND, OR) were used to refine the search strategies.
Articles were eligible if they examined relationships among environmental change, zoonotic diseases, human–animal interactions, and psychological outcomes. Empirical studies and high-quality reviews were considered. Studies unavailable in English, editorials without conceptual relevance, and articles that did not address mental health outcomes were excluded.
Because this viewpoint was conceptual and interdisciplinary, no formal quantitative risk-of-bias assessment was performed. The synthesis instead emphasized consistency of findings across disciplines and prioritized recent, high-quality sources. Although literature search was not systematic, the search was designed to capture a broad range of interdisciplinary evidence relevant to mental health and One Health.
Environmental Change and Mental Health
Climate-related events, including floods, droughts, and heatwaves, are associated with increased risks of anxiety, depression, and post-traumatic stress disorder [
8,
9]. Environmental change can also affect mental health indirectly by causing displacement, livelihood insecurity, and social disruption.
The concept of eco-anxiety describes distress related to environmental crises [
11–
18]. In many low- and middle-income settings, however, psychological distress is not confined to future-oriented concern about environmental decline; it is often rooted in immediate threats to livelihoods, food security, and daily survival [
13,
14].
Populations that depend on environmental stability may experience chronic stress when ecological uncertainty threatens income, food systems, or community stability [
6,
7]. These findings highlight the relevance of environmental determinants within a One Health perspective.
Zoonotic Disease Outbreaks and Psychological Consequences
Zoonotic disease outbreaks can produce psychological effects that extend beyond fear of infection. The coronavirus disease 2019 (COVID-19) pandemic showed how infectious disease crises may generate distress through social isolation, grief, uncertainty, stigma, and economic instability [
19].
COVID-19 also illustrates how zoonotic events can activate several overlapping pathways of mental health risk. Fear of infection, disruption of social networks, stigma toward affected groups, and economic insecurity contributed to the increased global prevalence of anxiety and depression [
19].
Healthcare workers, farmers, and animal handlers may also experience occupational stress during outbreak responses.
Human–Animal Relationships and Psychological Well-Being
Human–animal interactions can affect mental health in protective and adverse ways. Companion animals may provide emotional support and reduce loneliness, especially for individuals experiencing social isolation or psychological distress. Animal-assisted interventions have also shown benefits for some mental health conditions.
Conversely, communities that depend on livestock may experience distress when disease-control measures require animal culling or restrict animal trade. These experiences reflect the emotional, cultural, and economic dimensions of human–animal relationships, which are often overlooked in conventional biomedical models of health, especially in Indigenous communities. Incorporating these perspectives into One Health research may improve understanding of the broader social and psychological consequences of animal health policies [
16].
Conceptual Integration of Mental Health into One Health
I propose a conceptual framework in which mental health operates through three interconnected One Health pathways: (1) environmental pathways, (2) zoonotic and health-system pathways, and (3) socio-ecological pathways.
These pathways interact dynamically and shape psychological outcomes across populations. The framework builds on prior conceptual work linking environmental change and mental health [
4,
5,
10,
19–
21].
Recognizing mental health as a cross-cutting component of One Health expands the framework beyond infectious disease and environmental risk alone. It also supports more comprehensive, preventive, and equitable public health strategies in the face of complex global challenges (
Figure 1).
Mental health is positioned as a cross-cutting dimension within the interconnected domains of human, animal, and environmental health. The framework includes three pathways: environmental pathways, including climate change and ecological disruption; zoonotic and health-system pathways, including infectious disease outbreaks and response measures; and socio-ecological pathways, including livelihood instability and human–animal interactions. These pathways interact to influence psychological outcomes at individual and population levels. The outer layer represents policy integration, surveillance systems, and community resilience mechanisms that can help operationalize mental health within One Health.
Illustrative Case Examples Across One Health Pathways
The proposed pathways can be clarified through real-world examples that show how environmental, zoonotic, and socio-ecological processes affect mental health.
Environmental Pathway
The Minamata disease incident in Japan shows how ecological contamination can produce long-term neurological and psychological consequences for affected communities. Abnormal behavioral changes were first observed in cats exposed to methylmercury-contaminated environments; this phenomenon, later described as “dancing cat disease,” preceded recognition of human illness [
22,
23].
These observations showed that animal health can serve as an early warning sign of environmental toxicity and its behavioral and psychological effects. In affected human populations, Minamata disease was associated with severe neurological impairment as well as social stigma, anxiety, and long-term psychological distress [
24]. The case illustrates how integrated observation of environmental, animal, and human health can support earlier detection and inform preventive public health strategies, including strategies relevant to mental health.
Zoonotic and Health-System Pathway
The COVID-19 pandemic provides a clear example of how zoonotic disease outbreaks can generate widespread psychological effects. Quarantine, isolation, and movement restrictions contributed to anxiety, depression, and social distress, while stigma, misinformation, and uncertainty intensified mental health challenges [
19,
20]. These findings support the inclusion of mental health in outbreak preparedness, risk communication, and response planning within One Health systems.
Socio-Ecological Pathway
In agrarian communities affected by climate variability, particularly those in drought-prone regions, livelihood instability has been associated with psychological distress and elevated suicide risk among farmers [
25,
26]. These settings show how environmental stressors, economic vulnerability, and social conditions can converge to affect mental health. Addressing these risks requires integrated interventions that combine environmental management, livelihood support, and accessible mental health services.
Together, these examples show that mental health outcomes can emerge from interactions among ecological, biological, economic, and social systems. Recognizing these linkages strengthens the conceptual basis of One Health and points to opportunities for predictive, preventive, and community-based public health strategies that include mental health as a core concern.
Policy and Research Implications
To operationalize mental health within One Health, the following strategies may be considered: (1) integrating mental health indicators, such as the prevalence of psychological distress and mental health service utilization, into existing One Health surveillance systems and zoonotic disease monitoring platforms; (2) embedding psychosocial support services in climate adaptation and disaster-response programs, particularly in high-risk and vulnerable regions; (3) developing interdisciplinary training programs for mental health professionals, veterinarians, environmental scientists, and public health practitioners; (4) strengthening community-based mental health services and psychological first aid in regions affected by environmental change, including livelihood-support and resilience-building interventions; and (5) incorporating mental health preparedness into zoonotic outbreak planning, including risk communication strategies and support for frontline workers.
These strategies move the discussion from conceptual inclusion to practical implementation. They identify ways to measure mental health outcomes, build psychosocial support into climate and outbreak responses, and align One Health practice with global policy directions on climate change and mental health [
27]. Collectively, they frame mental health as a measurable, actionable, and system-level component of One Health.
Limitations
This viewpoint is limited by the emerging evidence base at the intersection of mental health and One Health. Much of the literature consists of narrative reviews, and relatively few empirical studies directly examine these relationships.
Mental health effects also vary across sociocultural and geographic contexts. In many settings, distress is shaped less by future-oriented environmental anxiety than by immediate livelihood concerns.
Conclusion
Mental health remains underrepresented in the One Health framework. Incorporating mental health into One Health can strengthen public health responses and support more holistic and resilient systems. Recognizing and operationalizing mental health within One Health is therefore an important step toward more comprehensive, preventive, and equitable global health systems.
HIGHLIGHTS
One Health has largely prioritized infectious diseases and environmental threats, while mental health remains underrepresented. Climate change, zoonotic outbreaks, and human–animal–ecosystem relationships can affect mental health through interconnected pathways. Integrating mental health into One Health can strengthen surveillance, preparedness, and response. A pathway-based approach may support more holistic, preventive, and equitable global health strategies.
Article information
Ethics Approval
Not applicable.
Conflicts of Interest
The author has no conflicts of interest to declare.
Availability of Data
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Figure 1.Conceptual integration of mental health within the One Health framework.
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