Statement

Alzheimer's disease is not a myth but reality: challenges for the 21st century

9 June 2010, London, UK

Alzheimer's Disease International and its member organisations throughout the world believe that Alzheimer's disease and other forms of dementia have a profound impact on those with the illness and their families. For people aged over 60 it is the second leading cause of years lived with disability (World Health Organisation, 2004).

With the ageing of the world's population and the increasing number of people aged over 60 there will be a substantial increase in the number of people with dementia. Nearly doubling every 20 years from 35.6 million in 2010 to 65.7 million in 2030 and 115.4 million in 2050(Alzheimer's Disease International, 2009).

The risk for dementia increases with increasing age, the incidence and prevalence roughly doubling for each five-year increment in age after the age of 60 years. Thus, dementia, in common with most other chronic diseases is an age-associated condition. That is not to say that dementia is a normal part of ageing. Nobody makes that claim for breast cancer or stroke, although the patterns of association with age are similar. It is in fact the rule rather than the exception that most diseases increase with age but they all remain diseases and real pathology that require attention. Osteoporosis, prostate diseases, delirium etc are all very common in old age. The case of dementia is no less. Even among those aged 80 years and over, the majority do not have dementia. The natural process of brain ageing is now quite well understood. The brain shrinks in size progressively from the mid-teens onward. Slow progressive deterioration in some cognitive functions is detectable from the sixth decade onwards. However, this is offset by increases in wisdom, knowledge and understanding, and does not limit normal daily activities.

Alzheimer's disease and other forms of dementia are not limited to older people but also afflict people as young as 30-50 years, often with a familial basis. One cannot refer to early onset Alzheimer's disease as a reflection of advanced aging.

Dementia is a syndrome characterised by abnormally rapid and progressive cognitive decline, sufficient to lead to significant disability, loss of independence and needs for care. It is invariably associated with one or more of a number of brain pathologies, including but not limited to amyloid and tau protein deposition (Alzheimer's disease), cerebrovascular disease ('vascular dementia'), cortical Lewy bodies ('Dementia with Lewy Bodies') and frontotemporal degeneration ('Fronto-temporal dementia'). It is increasingly understood that while pure forms of these dementia subtypes are sometimes seen, mixed forms are much more common. It is probably for this reason that there is not a clear or absolute correlation between the severity of these pathologies and the presence or severity of the clinical dementia syndrome. The complexity of the pathological process and our current partial understanding of the interactions between the different elements involved is, of course, no reason to question its very existence. Dementia is also related to well known brain neurological diseases such as Parkinson's disease which sometimes antedate or predate or occur simultaneously with dementia.

Most governments and their health and welfare systems are not prepared for the necessary growth in services to cope with the forecast rapid increase in numbers of people with dementia. Initially, people with dementia need support to look after themselves in their own homes; as the illness progresses they become increasingly dependent on help from others for feeding, dressing and personal hygiene.

The passport to support and services for people with dementia and their families is the diagnosis of dementia. To call the disease a myth (Whitehouse 2008), affects peoples' access to care and treatment. Research holds out hope that, in the future, diagnosis may be made earlier and more reliably (Dubois B et al, Lancet Neurology, 2007; (Reisberg and Gauthier, 2008, Jagust et al., 2009, Petersen and Trojanowski, 2009), and that the different causes of dementia and their underlying pathologies will be better understood (Aisen, 2009), leading to more effective treatments and delay or even prevention of dementia (Khachaturian and Khachaturian, 2009). In the meantime, existing evidence-based pharmacological and psychological treatments can improve cognitive function, make behavioural problems easier to manage, and reduce strain on carers. Early diagnosis, coupled with education, treatment and long-term support is the aim of recently initiated national dementia strategies in several high income countries (Australian Health Ministers' Conference, 2006, Banerjee and Wittenberg, 2009, Department of Health, 2009). A similar but more incremental approach is advocated for low and middle-income countries, starting with diagnosis and delivery of basic services from primary care (Prince et al, 2009, Dias et al 2008, and WHO mhGAP reference).

Ask someone with dementia who cannot remember conversations or how to perform simple tasks or ask a caregiver who is burdened and stressed by providing 24/7 care whether Alzheimer's is illusory. Ask scientists whether one pathology - the plaques and tangles in AD - is mythical, but others such as multiple strokes or familial fronto-temporal progranulin accumulation are not. The answers will all be the same.

In all parts of the world research has shown that the majority of people with dementia are not identified and that neither they nor their families receive any assistance. The greatest barriers to access to health and care services are lack of recognition, fear and stigma. With denial of access to care, the burden of dementias will be even greater. Demystifying Alzheimer's disease and other dementias, bringing them out in the open and demonstrating how people with dementia and their families can be helped are global priorities.

Daisy Acosta, Chairman Alzheimer's Disease International

Bengt Winblad, Chairman ADI Medical and Scientific Advisory Panel

References

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