In 2002 all three of the PACE trial's principal investigators, along with Aylward, Waddell and Wessely, contributed to a conference and book which promoted the use of the biopsychosocial model.[127] The book was made up of conference papers and transcripts of discussions, and includes Waddell explaining how the biopsychosocial model was gaining political influence:"It is all about money. The main thing was to persuade the treasury that there was an opportunity for keeping costs down, particularly over the longer term."
In response to another participant saying "if you go to Gordon Brown (UK Chancellor) and say, 'We can prove to you that if we address this issue, we can save £2 billion', then you will have his full attention", Mansel Aylward replied: "That is the approach that has been taken, but not in such a robust fashion."[127]
Their discussions explained how, within government, the antipathy caused by the view that the biopsychosocial model lacked a hard evidence base had been overcome by the softer evidence of "authoritative and expert opinion".