Climate change is widely known to affect physical health — but new research suggests the mental health toll could be enormous.
A study published in The Lancet Planetary Health projects that rising temperatures could lead to hundreds of millions to billions of additional anxiety and depression symptom-days each year across the United States, with the greatest burden falling on low-income communities and parts of Appalachia.
Using national mental health survey data and projections from multiple climate models, researchers estimate that 1–6°C of warming could result in:
- 401 million to 1.8 billion additional anxiety symptom-days annually
- 329 million to 1.4 billion additional depression symptom-days annually
- $24–$104+ billion per year in economic damages from these mental health impacts
The analysis draws on data from the Centers for Disease Control and Prevention’s Behavioral Risk Factor Surveillance System and climate projections used in the United States Environmental Protection Agency’s Climate Change Impacts and Risk Analysis framework.
Key findings:
- Each additional degree of warming could add about one extra anxiety or depression day per person per year
- Low-income Americans face significantly higher impacts
- Appalachia is projected to experience the largest increases
- Heat — not precipitation — is the main driver
The paper is available here: https://www.thelancet.com/journals/lanplh/article/PIIS2542-5196(25)00305-5/fulltext