Mental health impacts of climate mitigation and adaptation interventions in high income countries: A scoping review✰,✰✰

Introduction: Interventions to mitigate and adapt to climate change are increasingly recognised for their potential co-benefits to mental health, although evidence is fragmented. Understanding these co-benefits is important to inform interventions that maximise mental health gains and avoid unintended harms. Methods: We conducted a scoping review of peer-reviewed primary studies (2015-2025) to map and characterise evidence on the mental health impacts of climate mitigation and adaptation interventions on adults and children in high-income countries. MEDLINE, Web of Science, PsycINFO were searched and study quality was appraised using the Mixed-Methods Appraisal Tool. Results: Seventeen studies met our inclusion criteria, with most (76%) from the UK or North America. 71% were quantitative quasi-experiments;one was a randomised controlled trial; only two studies were appraised as high quality. Interventions included home retrofits (n = 9), urban greening (n=3), renewable energy (n=2), clean air zones (n=1), diet (n=1), and behaviour change (n=1). Only one study focused on children. Fourteen (82%) reported at least one improvement in mental health or wellbeing, including all home retrofit studies. Urban greening interventions showed mixed findings, while wind turbines were associated with some negative mental health impacts. Conclusion: The review suggests climate interventions can offer mental health co-benefits although existing evidence is limited and effects vary by context. Considering mental health outcomes in the design and evaluation of climate interventions could enhance equity, effectiveness, and public acceptability. Future research should use consistent outcome measures, disaggregate results by population group, and expand to underexplored sectors and regions.