Mental disorders, including depression and anxiety, rank among the leading causes of disability worldwide. Emerging evidence suggests that critical incidents occurring at the global and regional level, defined as events impacting large groups of individuals and disrupting social and public services, can exacerbate the risk of mental ill health. In this talk, Dr Omid V. Ebrahimi discusses how critical incidents, such as infectious disease outbreaks and economic recessions, impact the onset of mental disorders and can alter human behaviour during moments when societal cohesion is most crucial. Drawing on his research into the COVID-19 pandemic, this discussion aims to deepen our understanding of how large-scale societal phenomena interact with individual psychological outcomes, and how insights from past crises can inform strategies for future preparedness and resilience.