Systematic review and meta-analysis of interventions for mental health in extreme weather events

Clinical Snapshot

Key Findings

• P Value: Not explicitly reported but confidence intervals exclude null

• Effect Size: SMD -2.92 (intervention-control studies) and SMD -0.71 (before-after studies)

• Primary Outcome: PTSD symptoms showed significant improvement

• Nnt Or Sensitivity: Large effect sizes suggest clinically meaningful improvements across all mental health domains

• Confidence Interval: 95% CI (-4.53 to -1.31) and 95% CI (-0.95 to -0.48) respectively

Clinical Application

Implementation depends on disaster preparedness infrastructure and trained mental health professionals Highly relevant given Australia's exposure to bushfires, floods, and extreme heat; could inform state emergency management plans and Medicare-funded mental health services Individuals exposed to extreme weather events including floods, hurricanes, bushfires, and heatwaves

Abstract

INTRODUCTION: Climate change leading to extreme weather events (EWEs) poses critical threat to human health, including mental well-being. As the effects of climate change are becoming more pronounced, there is a need to identify effective interventions to mitigate the mental health impacts. METHODS: The aim of this review was to synthesise the existing literature on interventions to prevent and manage mental health symptoms in people affected by EWEs. We conducted a comprehensive literature search in MEDLINE, EBSCO CINAHL and Cochrane till 7 February 2024 and in Web of Science and EMBASE till 20 February 2024. Randomised controlled trials (RCTs), quasi-experimental studies and before-after study designs were included. Our search yielded 11 083 potentially relevant papers, which were screened by titles and full texts and 33 studies were finally included in the review. We recorded the study, participants, intervention, disaster and other relevant data on Excel in duplicate. We conducted a meta-analysis separately for intervention-control and before-after studies using Review Manager 5.4. The Cochrane Risk of Bias tool II was used to assess risk of bias in RCTs and the risk of bias in non-randomised studies of interventions tool for quasi-experimental and before-after designs. Main outcomes were symptoms of post-traumatic stress disorder (PTSD), depression, anxiety, stress, general functioning and well-being. RESULTS: There was significant improvement in mental health symptoms following implementation of various interventions, leading to a decrease in PTSD symptoms (standardised mean difference (SMD) -2.92, 95% CI (-4.53 to -1.31), six intervention-control studies and SMD -0.71, 95% CI (-0.95 to -0.48), five before-after studies), depression symptoms (SMD -0.28, 95% CI (-0.53 to -0.03), three intervention-control studies and SMD -1.00, 95% CI (-1.41 to -0.59), 11 before-after studies), anxiety symptoms (SMD -0.38, 95% CI (-0.69 to -0.06), two studies and SMD -0.35, 95% CI (-0.47 to -0.23), eight before-after studies), stress symptoms (SMD -0.82, 95% CI (-1.10 to -0.53), two before-after studies), general functioning impairment (SMD -1.22, 95% CI (-1.73 to -0.70), three before-after studies) and an improvement in well-being (SMD 0.29, 95% CI (0.15 to 0.42), three intervention-control studies and SMD 0.67, 95% CI (0.25 to 1.09), two before-after studies). CONCLUSION: There are existing interventions to improve mental health after an EWE, and these should be integrated into all relevant disaster management plans.

References

1. 1.Das, J. K., Ali, A., Jangda, A. T., Riaz, N., & Bhutta, Z. A. (2026). Systematic review and meta-analysis of interventions for mental health in extreme weather events. BMJ Global Health, 11(5), e020407. https://doi.org/10.1136/bmjgh-2025-020407