The Surveys of Psychiatric Morbidity aim to provide information about the prevalence of psychiatric problems among people in Great Britain, as well as their associated social disabilities and use of services. The surveys covering adults in private households (undertaken in 1993, 2000, 2007 and 2014) and children and adolescents (1999, 2004 and 2017), are detailed elsewhere on the Catalogue. The surveys detailed on this page were designed to show the prevalence of psychiatric morbidity in a series of marginalised populations: adults in institutions specifically catering for people with mental illness (1994); homeless people (1994); prisoners (1997); and children and young people looked after by local authorities (2001/2). These surveys provide key context for understanding mental illness in Britain and for informing initiatives in this area.