The theme of this year’s World Mental Health Day, on Oct 10, is increased investment in mental health. Why invest, and why now? The answer is simple. At the best of times, good mental health is needed for a society to thrive. During a pandemic, good mental health is more important than ever. Without a focus on mental health, any response to COVID-19 will be deficient, reducing individual and societal resilience, and impeding social, economic, and cultural recovery.2020 has been a difficult year for mental health. The threat of infection, repeated lockdowns, social isolation, and economic uncertainty have created widespread fear and anxiety. A Rapid Review published in The Lancet showed the negative psychological effects of enforced quarantines. Many people who previously thought themselves unaffected by mental health issues have discovered that they, too, are vulnerable. Those with pre-existing mental health conditions have often found their difficulties increased. The precise neurological and psychiatric consequences of infection, meanwhile, remain unknown but demand careful monitoring. What investment is needed from governments and non-governmental organisations to mitigate the mental health impact of COVID-19 and, more importantly, to improve mental health globally?