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Climate-related disasters can leave lasting psychological effects, and the burden may not be shared equally. A systematic review by Mahmood and colleagues suggests that people facing social and economic disadvantage may be more likely to experience poor mental health after events such as floods, hurricanes, wildfires and heatwaves.
The findings add to the World Health Organisation’s description of climate change as one of the greatest threats to global health in the twenty-first century. They also underline that the consequences of climate change are shaped not only by the event itself, but by people’s housing, finances, social support and ability to recover.
What the review examined
The researchers examined studies published up to 17 July 2023. The review covered floods, hurricanes, wildfires, heatwaves, droughts and long-term exposure to rising temperatures. It focused on lower-income groups, minoritised ethnic groups, indigenous populations and people experiencing housing insecurity.
The mental-health outcomes included depression, anxiety, psychological distress and post-traumatic stress disorder (PTSD). Of 2,179 records initially identified, 32 studies were included in the final narrative synthesis. Most examined acute events, particularly tropical cyclones.
Eighteen studies reported poorer mental-health outcomes among disadvantaged groups. Five reported mixed findings, while nine found no evidence of worse outcomes. Taken together, the review identified a possible pattern of greater risk, but not a consistent result across every study.
Why disadvantage may increase risk
People with fewer financial, social or housing resources may be more exposed to climate-related hazards. They may also have fewer opportunities to evacuate safely and face greater obstacles when replacing belongings, finding stable housing or rebuilding their lives afterwards.
The review suggested that inequalities may reflect greater exposure, greater material and personal losses, and fewer resources for recovery. Displacement, deaths and loss to follow-up may also mean that research underestimates longer-term effects among the people most severely affected.
The experience of the 2018 Camp Fire in Paradise, California, illustrates the wider impact of disaster. Survivors described losing not only their homes, but also their sense of identity, safety and community. Such losses can affect psychological wellbeing alongside the immediate danger and disruption caused by a fire.
What individual studies reported
- One study found that participants with lower incomes were nearly four times more likely to experience severe mental-health problems than the study’s reference group.
- In a study of long-term heat exposure, people with lower monthly incomes reported more severe psychological symptoms than those with higher incomes.
- One study reported PTSD criteria in 9.5% of participants from minoritised ethnic minority groups, compared with 4.4% of participants from other ethnic groups. This difference was not statistically significant.
- Evidence concerning indigenous populations was scarce. After a tropical cyclone, patterns of PTSD and depression emerged during the following 12 months, although the findings were not compared with other populations.
- For flood-like events, indigenous populations were about twice as likely as non-indigenous groups to experience probable anxiety and depression, with reported likelihoods of 1.89 and 1.84 respectively.
- People living in informal settlements experienced a larger increase in depression scores after floods in one study.
Why the findings need careful interpretation
The review authors advised caution because the studies differed substantially in their populations, climate exposures, designs and ways of measuring mental health. Most were cross-sectional, meaning they captured information at a particular point in time. This limits conclusions about whether a climate-related event directly caused a mental-health outcome and leaves open the possibility that other factors influenced the results.
The review was limited to research published in English, so relevant evidence from low- and middle-income countries may have been missed. Four included studies also drew on the same sample of low-income mothers who survived Hurricane Katrina, which may affect how broadly the results can be applied.
Evidence about droughts and combined climate exposures was limited and inconsistent. The review also did not explicitly examine how overlapping disadvantages—such as low income, ethnicity and housing insecurity—may interact. Quantitative research dominated the evidence, leaving lived experiences and wider cultural and community effects less fully represented.
The wider meaning
Climate change is a mental-health issue as well as an environmental and physical-health concern. The review does not show that every disadvantaged person will experience worse mental health after a disaster. Instead, it points to conditions that may increase risk and make recovery harder.
Understanding those conditions matters for how communities assess climate-related harm and plan support after an event. It also highlights the need for research that includes underrepresented populations, follows people over time and better reflects the combined effects of financial insecurity, housing instability and social marginalisation.
AI tools were used to assist with the preparation of this article.
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