ABSTRACT
This chapter reviews the findings of a research study which measured the prevalence of mental illness and substance misuse co-morbidity (hereafter referred to as co-morbidity) in substance misuse and mental health treatment populations. The study was funded by the Drugs Misuse Research Initiative (DMRI) in 2000 and completed between 2001 and 2002. Although the chapter reports data collected seven years prior to the publication of this volume, we will argue that the findings are still relevant. First, the study has not been replicated and so still provides the best UK evidence about the epidemiology of co-morbidity in treatment populations. Second, while the study findings have had an influence on policy (which merits documentation), some key findings about the extent of non-psychotic mental illness within drug treatment populations have not been acted upon. Third, as we argue in the conclusions, a re-assessment of these findings is timely given the development of care co-ordination (see Chapter 5) and efforts to increase the capacity of services to provide psychosocial interventions.
