Climate change as a threat multiplier: conflict pathways, inequities, and mental health impacts.

Climate change is increasingly recognized as a major driver of global instability, understood here as the interconnected disruption of social, economic, political, and security systems, acting as a threat multiplier that intensifies existing vulnerabilities. Its mental health impacts emerge through direct exposures-such as extreme heat, wildfires, floods, and other disasters-and through indirect pathways, including livelihood disruption, resource insecurity, displacement, and social fragmentation. These pressures contribute to heightened risks of post-traumatic stress disorder, depression, anxiety, suicidality, cognitive distress, and substance use, particularly in conflict-affected settings. This narrative review synthesizes evidence on how climate change amplifies conflict dynamics and inequities, and how these mechanisms shape mental health outcomes. A focused search was conducted in Web of Science, PubMed/MEDLINE, and Scopus for peer-reviewed literature published from 2015 onward, and findings were examined using an inductive thematic approach. Results show that vulnerable groups-including children, adolescents, women, Indigenous peoples, migrants, individuals with low socioeconomic status, and those with preexisting mental disorders-face disproportionately high risks. Significant gaps persist in longitudinal research, standardized exposure assessment, intervention evaluation, and policy integration. Addressing the mental health consequences of climate change requires coordinated action across clinical care, community resilience efforts, and public policy, with mental health firmly embedded in climate adaptation and disaster preparedness strategies.