“…Despite the centrality of vulnerable young people to the Government's drug strategy, relatively little reliable evidence is available about the patterns of drug consumption among such groups (Hammersley & Pearl, 1997). Existing evidence has consistently reported higher levels of substance abuse by these young people compared with their contemporaries who are not considered to be vulnerable or ''at risk'' (Audit Commission, 1996;Flood-Page, Campbell, Harrington, & Miller, 2000;McCrystal, Higgins, Percy, & Thornton, 2005;Melrose, 2000;Miller & Plant, 1999;Osler, Street, Lall, & Vincent, 2002;Powis et al, 1998).…”