LONDON, ENGLAND - APRIL 19:  Catherine, Duchess of Cambridge with runner Alex Stanley, put a Heads Together headband onto the Kensington Palace post-box in support of the Royal Mail wrapping 70 post-boxes that line the 2017 Virgin Money London Marathon route ahead of a reception for Team Heads Together, at Kensington Palace on April 19, 2017 in London, England. Heads Together is spearheaded by the Duke and Duchess of Cambridge and Prince Harry,  in partnership with eight leading mental health charities that are tackling stigma, raising awareness, and providing vital help for people with mental health problems.  (Photo by Chris Jackson - WPA Pool/Getty Images)