One of the challenges for services in the UK has been how best to meet the needs of those people who experience severe mental health problems and use drugs and alcohol problematically. It is now well-documented in the international literature that the coexistence of severe mental health and substance misuse problems are common (e.g. Regier et al, 1990; Krausz et al, 1996; Menezes et al, 1996; Fowler et al, 1998; Mueser et al, 2000; Graham et al, 2001) and often correlated with a number of adverse outcomes (Smith & Hucker, 1994; Johnson, 1997; Mueser et al, 2000). Integrated treatment approaches developed in the USA for this client group (e.g. Drake & Wallach, 2000; Drake et al, 2001), and although they offer much food for thought and some direction, they could not be wholly imported and implemented in the UK because of significant differences in the contextual factors that guide service provision in the two countries. The challenge in the UK has been to develop effective services that fit with the unique community-based treatment approaches for substance misuse problems and mental health that have developed and historically offered separately and in parallel.