Current approaches to identifying the severely mentally ill.

Mental health care is expensive to provide and resources should be targeted. Possible approaches to such a prioritization are outlined. In the United Kingdom, care is to be provided on the basis of need. The key issue is then identifying the severely mentally ill, who are most in need of mental health care. Definitions of severe mental illness used in research studies are reviewed, indicating a lack of consensus about identifying this group. Current practice in England was surveyed, by obtaining written documentation from 20 agencies on the eligibility criteria they use for deciding whether someone should receive mental health care. Government departments, user groups and professional bodies were also surveyed. The findings indicate that definitions of severe mental illness use the five dimensions of safety, informal and formal support, diagnosis, disability and duration--the SIDDD dimensions. These dimensions offer a framework for developing definitions of severe mental illness at the local level, thereby identifying the priority group for mental health care.