Across Australia, communities are grappling with climate disasters that are striking more frequently and with greater intensity . Bushfires, floods and cyclones are no longer one-off events. And this pattern is predicted to worsen due to climate change.
Authors
- Ang Li
ARC DECRA and Senior Research Fellow, NHMRC Centre of Research Excellence in Healthy Housing, Melbourne School of Population and Global Health, The University of Melbourne
- Claire Leppold
Research Fellow, Disaster, Climate & Adversity Unit, Melbourne School of Population and Global Health, The University of Melbourne
As it becomes more common to face climate disasters again and again , what does this mean for the mental health and wellbeing of people affected?
In a new study published today in the Lancet Public Health, we found experiencing repeated disasters leads to more severe and sustained effects on mental health compared to experiencing a single disaster.
What we did in our study
We drew on ten years of Australian data (2009-19) from the nationally representative Household, Income and Labour Dynamics in Australia survey.
Specifically, our study involved data from 1,511 people who experienced at least one disaster. We tracked them from the year before the first disaster, at the first disaster, and, where applicable, each subsequent disaster, and a few years after each disaster.
We also included 3,880 people who did not experience disasters during this time but shared similar demographic, socioeconomic, health and place-based characteristics for comparison.
We measured exposure to climate disasters based on whether respondents reported a weather-related disaster (for example, flood, bushfire or cyclone) damaged or destroyed their home in the previous year.
The mental health outcomes were measured using two questionnaires commonly administered to assess depression and anxiety disorders ( the 5-item mental health inventory ) and psychological distress ( the Kessler Psychological Distress Scale ).
Cumulative effects
Our results show mental health declines became more severe with repeated disasters.
The graph below plots the mental health trajectories for everyone in our study who experienced at least one disaster, and the control group who did not experience any disasters. We looked at a maximum of three disasters in the study due to data availability.
It shows experiencing one disaster led to a decline in mental health during the disaster year, followed by a recovery to pre-disaster levels in the post-disaster period.
However, with repeated disasters, mental health trajectories declined further and it took longer to recover to pre-disaster levels.
We also found experiencing an additional disaster close to a previous disaster (for example, one or two years apart) was linked to greater mental health declines than disasters that were spaced further apart.
Some risk factors
We observed that certain factors consistently shaped mental health outcomes. For instance, having social support was consistently a protective factor, while having a long-term health condition consistently increased the risk of poorer mental health. This was true regardless of the number of disasters someone experienced.
On the other hand, some risk factors became stronger with each disaster. In particular, households with lower incomes, those in rural areas, and younger people appeared to experience greater effects of cumulative disasters.
There are some limitations to our research. For example, the data we had did not detail the type or severity of each disaster. It also was limited in what it could tell us about the mental health effects of three or more disasters.
Nonetheless, our study provides novel insights into the mental health consequences of multiple climate disasters. This highlights the need for better support for communities facing an increasing number of emergencies.
Our findings also align with other studies that have observed increasing risk to mental health with multiple disasters .
At the same time, our findings add a new perspective by showing how trajectories can change over time. People's mental health often recovers to pre-disaster levels after a single disaster, but repeat disasters can delay or halt this recovery.
Why might repeated disasters lead to worse mental health?
Repeated disasters, especially when they occur in close succession, can lead to cumulative stress driven by trauma and uncertainty. This can create a reinforcing cycle. People already facing social disadvantages - such as poor health and low income - are more likely to be exposed to disasters. In turn, these events disproportionately affect those facing existing disadvantages.
The result is a compounding effect that can contribute to worsening mental health outcomes and slower recovery over multiple disasters. This means disasters are an issue of social equity and must be considered in efforts to reduce poverty and improve social outcomes, as well as health outcomes.
Repeated disasters in particular can drain financial, social and community resources. They can exacerbate existing strain on household savings, disrupted social ties due to displacement, and reduced access to services after disasters - especially in rural areas .
What can we do to support people through multiple disasters?
We need to transform the way we think about disasters. It's estimated children born today will experience up to seven times the number of extreme weather events across their lifetimes than someone born in 1960.
We are starting to get a better picture of what people need to recover from climate disasters. Our research points to the need for clinical services (for example, GPs) to screen for past disaster exposures in mental health assessments.
Emergency services need to plan services to reach at-risk groups during disasters. They also need to ensure recovery planning considers the effects of past disasters, for example by making sure support programs are not just tied to one disaster, but can be used across multiple.
The current approach to emergency services that looks at " one disaster at a time " doesn't work anymore. As the climate continues to change, we urgently need to consider the effects of multiple disasters in public health, welfare and disaster services.
Ang Li receives funding from the Australian Research Council.
Claire Leppold does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.
