ABSTRACT
According to the World Health Organization (World Health Organization/ WHO 2005a) there are more than 450 million people with mental, behavioural or neurological problems throughout the world. In the USA, for example, about one in four adults suffer from a diagnosable mental disorder in any given year (National Institute of Mental Health/ NIMH 2006a). This translates into just under 60 million people. Although mental ill-health is widespread, many of the costs are in respect of a much smaller population who exhibit severe and enduring mental distress ± about 1 in 17 people in the USA (ibid.). Such people are chronic users of mental health services. They are more likely to be hospitalized, sometimes under compulsory powers, and are in need of high-intensity intervention. Hence, although they may be small in number, such people represent a signi®cant investment in terms of services, time and expenditure, the most expensive being those detained in secure care.
