The wide diversity of liaison psychiatry services that exists across the UK is striking. It is clear that no one model fits all and that a number of factors including funding streams, historical factors and the enthusiasm and interest of clinicians working in this field have shaped the services in place today. Helpfully, a number of national policies released by the Department of Health over the past few years have begun to enshrine the provision of both a biopsychosocial and multidisciplinary approach to patient care in an increasing number of areas of physical health (see Suggested reading). The shift in delivery of medical care from hospitals to primary care may well influence where further developments within liaison psychiatry services occur.

This chapter is divided into a number of sections each describing a variety of service models in different areas, namely: A&E, wards in the general hospital, out-patient settings and primary care. In addition, a service model that includes the provision of in-patient liaison psychiatry beds is discussed. Finally, the Psychiatric Liaison Accreditation Network (PLAN), a recently launched initiative established to improve and raise the profile of mental health services to general hospitals across the UK and Ireland, is described.

Some services may have the funding and local champions to deliver a comprehensive service to many areas, whereas in others just a small specific development may be possible (e.g. a clinical and supervisory link with a palliative care multidisciplinary team). Wherever the service is to be developed there are four core principles that need to be considered:

1. the types of clinical problems encountered

2. the age groups the service will cover

3. the times of operation provided by the service

4. the nature of the service offered (i.e. assessment only or assessment and intervention).

Decisions made concerning these issues will in turn determine the most appropriate service model to develop and the size and skill-mix of the liaison team. Managerial arrangements and educational and training roles also need consideration. However, this chapter focuses on the clinical provision of services rather than the latter factors.