Dementia is a condition whose causes are poorly understood, which cannot be cured and for which current treatments of symptoms have at best marginal effects. Dementia affects a significant proportion of the population of elderly people in developed countries, and it is estimated that over half a million people in the UK have it. There are thus important implications for the health and social care resources required to support them.

The term dementia refers to a constellation of signs and symptoms reflecting global impairment of higher intellectual functions. It involves progressive deterioration of the brain, the principal causes of which are Alzheimer’s disease, strokes and alcoholism. That is, dementia refers to a cluster of disease processes. In its most severe forms it involves massive atrophy of the brain, with consequent deterioration of mental and physical functioning. Often, however, dementia does not progress beyond a mild form even though someone may have it for several years.

Dementia has always been thought of as an age-related condition, and has almost certainly become more prevalent as the numbers of elderly people have increased. It is, though, distinct from ageing, which is not an illness: the popular association of old age and senility is erroneous. Indeed, the identification of dementia associated with AIDS and HIV infections may come to change the general perception of dementia as a disease of old age. Dementia is an important component of more general changes both in the UK and other developed countries, where changes in the structure of populations suggest that financing health care, social care and pensions will pose serious challenges in the first quarter of the next century (OECD, 1988).

Yet this should not be taken to imply that we can only despair: informal care and statutory services can between them ensure that people with dementia have the highest quality of life possible, within the constraints imposed by their condition. A major task for service providers, from all sectors, is to ensure that people with dementia and their carers receive support appropriate to their needs. Current evidence, both from the UK and elsewhere, suggests that this is the exception rather than the rule.

The hope for ameliorating the effects of dementia still lies in the future. Researchers are beginning to unravel its causes, and this is an important step towards developing effective treatments. In particular, the origins of Alzheimer’s disease, the most common cause of dementia, are under intensive investigation. This review discusses the evidence and arguments about dementia, and looks at the current developments in research and in service provision which will shape the experiences of people with dementia in the future. In contrast with most earlier reviews, it seeks to bring together two topics that are normally discussed separately, namely the organisation of health and social services and the impact of pharmaceuticals. It seems very probable that their interaction will have a major impact on people with dementia during the 1990’s.

The next six chapters review the current status and future prospects for research and service provision for people with dementia. Chapter 2 examines the evidence on the prevalence and incidence of dementia, which suggests that precise estimates are difficult to arrive at, but that the numbers involved are large. Chapter 3 briefly presents the clinical picture presented by dementia, and Chapter 4 the pharmaceutical and other therapeutic strategies currently available. (An appendix reviews progress in understanding the causes of dementia). At this point the focus moves away from clinical issues. Chapter 5 considers the organisation of services for people with dementia, and discusses the role of informal carers. Then Chapter 6 reviews evidence on the cost and value of care for people with dementia. Finally, Chapter 7 looks at the major developments and policy issues which are likely to determine the experiences of people with dementia and their carers in the 1990’s.