Changes to mental health legislation are relatively rare. The new Mental Health Act 2007 (in force from 3 November 2008) in England and Wales updated the 1983 Mental Health Act ' to ensure it keeps pace with the changes in the way mental health services are-and need to be-delivered ' (Department of Health, 2008 , p. 4). Arguably the most dramatic changes affect the detention and inpatient care of individuals with personality disorder which partly drove the government ' s initial desire to update the legislation. From 1983 until the new Act was enforced, individuals with personality disorder who were assessed for formal detention in hospital were required to meet the legal criterion of ' psychopathic disorder ' and also be deemed ' treatable '. However, from November 2008 no separate legal category for personality disorder exists, merely the presence of ' mental disorder ' , and treatability has been sublimated into the ' appropriate medical treatment ' being available in the hospital. The legislative change from an individual needing to be ' treatable ' to a service having treatment for them is a subtle but important distinction and arose from growing government frustration with the way professional practice had developed under the old Act. Although the original so-called ' treatability clause ' was introduced into the 1983 Act partly to ensure that individuals who were admitted were able to benefi t from the treatment available, critics (for example Hoggett, 1990) argued that it became a tool for use by psychiatrists to avoid admitting the ' unmanageable ' on the grounds of ' untreatability '. Instead the new Act now allows for the detention of individuals with personality disorder even though they may refuse to engage in treatment or the treatment may not initially be effective for them.