How Do Climate Change and Disasters Affect Mental Health in Developing Countries?

What you need to know

• Climate change and climate-related disasters are associated with increased rates of mental disorders like PTSD, depression, and anxiety in low- and middle-income countries.
• Most research has focused on the mental health impacts of specific disasters like floods and storms, with less on gradual climate change effects.
• There is a need for more long-term studies and research in underrepresented regions like Africa and South America to better understand these impacts.

Climate change as a global health threat

Climate change is widely considered one of the biggest threats to global health in the 21st century. As global temperatures rise due to human activities, we are seeing more frequent and severe extreme weather events like floods, storms, and heat waves. These climate-related disasters, along with longer-term changes like rising sea levels and crop failures, can have major impacts on both physical and mental health.

This review focused specifically on how climate change and climate-related disasters affect rates of mental disorders in low- and middle-income countries (LMICs). People living in LMICs are especially vulnerable to the health impacts of climate change for several reasons:

1. They are more likely to be directly exposed to climate-related disasters and environmental changes.
2. They often lack adequate infrastructure and resources to cope with these impacts.
3. Mental health care systems in many LMICs are already overburdened and underfunded.

Understanding how climate change affects mental health in these settings is crucial for developing effective policies and interventions to protect vulnerable populations.

How climate change impacts mental health

The researchers identified two main pathways through which climate change can impact mental health:

Direct impacts: These are the immediate psychological effects of experiencing climate-related disasters like floods, storms, wildfires, and heat waves. For example, surviving a devastating flood can lead to post-traumatic stress disorder (PTSD), anxiety, or depression.

Indirect impacts: These are the mental health consequences of broader, gradual changes related to climate change. For instance, rising temperatures and changing rainfall patterns may lead to crop failures, forcing people to migrate. This displacement and associated poverty can contribute to mental health issues.

Key findings on mental disorders

The review found 58 relevant studies from 11 different low- and middle-income countries, mostly in Asia. Here are some of the key findings:

Post-traumatic stress disorder (PTSD)

PTSD was the most commonly studied mental health outcome. Studies found PTSD rates ranging from 2.5% to 100% among people exposed to climate-related disasters, with most estimates falling between 10-30%. PTSD was especially common after floods and storms.

Depression

Many studies also looked at rates of depression after climate-related disasters. Prevalence estimates ranged widely, from less than 1% to over 60%. Several studies found depression rates between 20-40% in disaster-affected populations.

Anxiety

Anxiety disorders were also frequently studied, with prevalence estimates ranging from 0.1% to 44%. Climate-related disasters like floods and storms were associated with increased anxiety symptoms in multiple studies.

Other mental health impacts

A smaller number of studies examined other mental health outcomes:

• Acute stress disorder: Two studies reported rates of 2.2% and 22.5% after typhoons.
• Substance use disorders: Limited evidence suggested increased alcohol use in some disaster-affected populations.
• Suicide: A few studies found links between climate factors like drought and increased suicide risk.

Factors influencing mental health impacts

The review identified several factors that influenced how severely climate-related events impacted mental health:

• Disaster severity: More severe disaster exposure (e.g. injury, property damage, fear for one’s life) was generally associated with worse mental health outcomes.
• Time since disaster: Some studies found mental health symptoms improved over time, while others showed long-lasting impacts years after disasters.
• Social support: Having strong social connections and support systems appeared to protect against negative mental health impacts in some studies.
• Prior mental health: Pre-existing mental health issues increased risk for post-disaster mental disorders in some cases.

Limitations and gaps in current research

While this review provides valuable insights, the researchers also identified several important limitations and gaps in the existing literature:

Geographic gaps

Most studies were conducted in China, India, and Southeast Asian countries. There was a notable lack of research from Africa and South America, despite these regions being highly vulnerable to climate change impacts.

Short-term focus

The majority of studies looked at mental health impacts within one year of climate-related disasters. There is a need for more long-term studies to understand how these impacts evolve over time.

Limited study designs

Most studies (83%) used cross-sectional designs, which only provide a snapshot at one point in time. More longitudinal studies that follow people over time are needed to better understand cause-and-effect relationships.

Lack of comparison groups

Many studies only looked at disaster-affected populations without including a comparison group of people not exposed to the disaster. This makes it difficult to determine how much of the observed mental health burden is specifically due to climate-related events versus other factors.

Inconsistent measurement

Studies used a wide variety of tools and criteria to assess mental disorders, making it challenging to directly compare results across studies.

Implications for policy and practice

Despite these limitations, the overall evidence suggests climate change and climate-related disasters have significant negative impacts on mental health in low- and middle-income countries. The review authors argue this underscores the need to consider mental health in climate change policies and disaster response plans.

Some potential policy-level solutions they suggest include:

1. Increasing funding and access to mental health services in climate-vulnerable regions
2. Improving mental health surveillance and monitoring systems
3. Developing climate adaptation plans for mental health care systems
4. Providing specialized mental health training for disaster response workers

On an individual level, the review highlights the importance of social support in protecting mental health. Efforts to strengthen community connections and support systems may help build resilience to the psychological impacts of climate change.

Conclusions

• Climate change and climate-related disasters are associated with increased rates of mental disorders like PTSD, depression, and anxiety in low- and middle-income countries.
• More severe disaster exposure tends to result in worse mental health outcomes.
• There is a need for more long-term studies and research in underrepresented regions to better understand these impacts.
• Mental health should be a key consideration in climate change policies and disaster response planning in low- and middle-income countries.

By addressing the mental health dimensions of climate change, we can better protect vulnerable populations and build more resilient communities in the face of growing environmental challenges. However, more research is still needed to guide evidence-based interventions and policies, particularly in the most climate-vulnerable regions of the world.