The Spanish Flu is thought to have killed 50 million worldwide between 1918 and 1919, but there was a hidden impact on mental well-being. A century later, as the Covid-19 virus took hold in the early months of 2020, health organisations and mental health service providers began to warn of its deleterious effects on mental health. Frustrations and boredom arising from the impositions of lockdown, anxieties relating to finances and general health and the increased difficulties in accessing specialist mental health services for those that needed them have all been cited as potential triggers. With the global nature of the pandemic, the World Health Organization is just one of many national and international bodies to offer advice and support on this often-overlooked aspect of the novel corona virus. In medical circles, there has been concern from the start about the possible longer-term neuropsychiatric implications of having the virus. We know from the Spanish Flu that this is a very real danger, but, more than just acting as a warning, the past can also help us recognise the complex interplay of social, economic, physical, medical and psychological factors that arises in such situations.