A 2017 study, conducted by The Lancet Commission on Dementia Prevention, Intervention and Care, called dementia “the greatest global challenge for health and social care in the 21st century.” But you don’t need a study to tell you that. Ask friends and loved ones of the estimated 50 million people worldwide who have dementia (there’s a good chance you are one), and they’ll tell you about the worry, stress, sadness and devastation ...