LONDON, ENGLAND - MARCH 31: Norman Lamb, the Liberal Democrat party health spokesman, holds up a copy of a pamphlet entitled 'Manifesto for the Mind' during the launch of the Liberal Democrat NHS manifesto at a press conference on March 31, 2015 in London, England. The leader launched the Liberal democrat party's NHS manifesto on the second day of campaigning in what is predicted to be Britain's closest national election in decades. (Photo by Carl Court/Getty Images)