According to the latest research conducted by Alzheimer’s Research UK, a staggering one in three babies born this year are expected to develop dementia in their lives. There are already 800,000 people living with the condition, and this number will increase as the population ages. It is estimated that by 2050 two million people will be affected. The research has revealed that 37 per cent of females and 27 per cent of males born in 2015 will go on to develop dementia at some point in their lives. It has been labelled a ‘looming national emergency’, with the condition already costing the economy £28 billion a year. The figures have prompted officials to start a campaign that will encourage people to reduce their risk of the condition by leading healthier lifestyles. The journalist Sarah Rainey explores the reason why we still haven’t found a cure for dementia and the challenges facing scientists and doctors working in this area in her cover essay.