CHAPTER 1
Dementia in the new millennium
John P Wattis
A BRIEF HISTORY OF OUR UNDERSTANDING OF DEMENTIA
Dementia bears a stigma like other mental illnesses. Before effective pharmacological measures for mental illness were developed, that is before the last half of the last century, different models for understanding mental illness and different modes of treatment prevailed. The first positive post-medieval development was that of āmoral managementā or āmoral treatmentā of mental illness. Previously belief in demonology or views on the irrationality of people with mental illness had led to abuse and/or containment. Moral management brought about an engagement with the mentally ill person on an individual and collective level reflected in the modern Therapeutic Community movement. Reasoning and moral and emotional support produced good results in places like the Retreat in York, England and in other countries, too. The era of the large asylum and āmedicalisationā of mental illness followed. At the same time, the new discipline of psychoanalysis provided an explanation and treatment for some of the less severe mental disorders and had a wide impact on society. Critiques of an excessively medical model for understanding dementia1 have led to practical measures of the well-being of patients with dementia2 and recommendations for improved models of care.3 Today, biological, social and psychological factors are all recognised as important in the management of dementia.
Although conditions described in Roman times probably correspond to current diagnoses of dementia, the modern medical history of the condition begins in 1906 when Alzheimer, a German neuropsychiatrist and associate of Kraeplin, described a woman in late middle age with the clinical picture and pathology of the disease that now bears his name. At another time, he also described the pathology of vascular dementia. At the time most cases of dementia in old people were written off as āsenileā dementia or āsenilityā. Competing schools of neuropathology in Munich (Alzheimer) and Prague perpetuated this divide and the identity of Alzheimerās disease with most cases of āsenileā dementia was not widely realised for another half century.
In the mid-1950s Roth4 published an account of the natural history of mental disorders in old age that distinguished between āsenileā and āarterioscleroticā psychosis on the basis of their outcomes. Further studies established the epidemiology of mental disorders in late life5 and the quantitative pathology6 of Alzheimerās and vascular dementia. The deficiency of the neurotransmitter acetylcholine in Alzheimerās disease was recognised 10 years later7 and led to the development of the cholinergic hypothesis and therapies based on it. Initially these were based on attempts to increase the availability of choline by dietary supplementation with the precursor lecithin and subsequently on inhibition of the enzymes responsible for breaking down acetylcholine. In the meantime specialist mental health services for older people were developing and taking an interest in the positive management of people with dementia.8 At this time Alzheimerās and vascular dementia were regarded as the two main causes of dementia, accounting singly or in combination for 90% or more of all cases (see Chapter 2). There were a host of other rarer causes such as Pickās disease and the āmetabolicā dementias of vitamin B12 and thyroid deficiency (see Chapter 6). More recently, diffuse Lewy body dementia has been recognised,9 though it has still not been included in international diagnostic systems and there is still debate about its precise relationship with Alzheimerās disease, Parkinsonās disease and other psychiatric disorders.10,11 Often different types of pathology co-exist. The ānun studyā showed the importance of vascular damage in producing clinical dementia in patients with co-existing Alzheimer pathology,12 confirming earlier pathological studies.
THE BURDEN OF DEMENTIA
Dementia imposes a terrible burden on society. The social burden is greatly influenced by demography since dementia is predominantly a condition of very old people. Since the beginning of the 20th century, the proportion of people in the United Kingdom (UK) over the age of 65 has risen threefold. The proportion of very old has increased even more markedly. Other countries in the developed world have been through similar changes and these changes are likely to be experienced in an accelerated way in the developing world (see Chapter 2).
Society may also increase the personal burden on people with dementia and those who care for them by the way it reacts to people with dementia (see Chapter 10) and by placing them and their carers under economic pressure. Political decisions about eligibility for care services supported by the state affect the financial burden. There is need for a debate about why old people with dementia should receive less favourable social support than young people with physical disability. For individuals afflicted with dementia the eventual loss of capacity for independent living threatens to take away their autonomy. For family and other carers there is the constant worry about safety and the burden of directly or indirectly meeting the needs of those who find it increasingly difficult to care for themselves. In the UK around three-quarters of a million people are currently affected.13 In the United States (US) the comparable figure is around 5.3 million.14 Currently between 18 and 37 million people worldwide are estimated to have one or other type of dementia and projections suggest that by 2025 this number will nearly double, with nearly three-quarters living in developing countries (see Chapter 2). The cost in terms of lost human potential and burden on caregivers is vast; current annual costs in the US alone are estimated at nearly $150 billion. Despite the fact that dementia is concentrated in late life it ranks 13th in the World Health Organizationās list of causes of years lived with disability.15 What can be done about so great a burden?
WHAT WE CAN DO?
We need to respond to the challenge at a variety of levels, including the following:
ā¤ the international level
ā¤ the national level
ā¤ the level of the local community
ā¤ the level of the family
ā¤ the personal level.
Internationally, organisations like Alzheimerās International, the World Health Organization and the International Psychogeriatric Association are trying to prepare countries in the developing world for the explosion in the prevalence of dementia that an ageing population will bring. In the developed world, there is still a need to eradicate ageist attitudes to the provision of support and treatment for people with dementia. At the population level, our developing knowledge of the risk factors for various forms of dementia may well enable us to produce a relative reduction in the numbers of people affected. For example, raised diastolic blood pressure has been linked to increased risk of memory impairment and cardiovascular health and brain health seem inextricably linked. Evidence is emerging that a Mediterranean diet, physical exercise and brain āexerciseā may all have a role in delaying the onset or progress of dementia. The inflammatory response to infection in older people with Alzheimerās disease may produce a permanent worsening of the cognitive state, possibly through inflammation-like reactions in the brain, suggesting that attention to the physical health of people with early dementia is especially important. All these examples suggest immediate practical ways of reducing the population and individual risk of dementia. In addition, more fundamental genetic research is proceeding with three potentially important new genes reported in September 2009. These examples are taken from two months of reported research on the Alzheimerās Society website (www.alzheimers.org.uk and click through to āresearch newsā).
However, age remains the greatest risk factor for developing dementia, especially Alzheimerās disease and so all those public health and lifestyle measures that increase longevity are likely to increase the population at risk. This does not mean we should give up. Reducing the prevalence of disease and its impact are fundamental tasks for medicine, related disciplines and the whole of society.
The āidealā scenario would be to develop the capacity to identify people at risk of dementia and to reduce that risk by acceptable and inexpensive public health or specific treatment measures. Genetic risk factors are already identified and will be discussed in more detail in Chapters 2 and 3. Measures to eliminate these genes from the gene pool are likely to be impractical, morally unacceptable and have unforeseeable consequences. However, genotyping to identify āat riskā populations may, as our knowledge of the mechanisms of disease expands, enable preventive measures or early treatment at a pre-clinical stage before symptoms of disease develop. As new drugs are developed that interfere with the progression of Alzheimerās disease and as the population of the developing world ages dilemmas are likely to occur about the affordability of these drugs in poorer countries.
Local communities need to be helped to develop a better understanding of dementia and the issues that surround it so that families and people with dementia are treated as people and not marginalised. Old age psychiatry services, working through local government and primary care services, should see this education as one of their functions.
Families and individuals can take responsibility for lifestyle measures. At present avoiding smoking and excessive alcohol intake, a healthy diet, regular exercise, measures to reduce the risk of or treat high blood pressure and keeping the brain active can all be recommended as feasible ways of reducing risk. Once problems develop, positive management requires a bio-psycho-social model. A model that only considers one of these factors is wholly inadequate. Figure 1.1, taken from Practical Psychiatry of Old Age,16 emphasises that in dealing with any individual patient we need to take into account brain, body, senses and physical and social environment and the interaction between them.
Positive management of dementia consists of first making a diagnosis and excluding rare, potentially treatable causes of dementia such as thyroid deficiency. Specific treatment for Alzheimerās dementia now exists and is probably effective in some other forms of dementia too, though use of the drugs in England is constrained by government guidelines.17 The next step is to maximise the patientās capacity for independent living by optimising physical health, correcting deficiencies in hearing and sight and providing a supportive environment. Emotional and practical support to patients and carers requires collaboration across health and social care organisations. This kind of multi-layered approach fostered and was strengthened by the multidisciplinary approach to old age mental health services developed in the UK.18,19,20 Other inter...