Bioethics in the News - Dealing with the Alzheimer's "Tsunami"


Alzheimer's disease is an irreversible and progressive brain disease that slowly but inexorably destroys memory, thinking skills, and eventually the ability to carry out the simplest tasks. The staggering growth in persons being diagnosed with Alzheimer's has led many to describe it as a "tsunami in waiting." According to recent statistics one in two Americans in their eighties have this disease, and one in ten over sixty-five. Alzheimer's death rates are up 47 percent since 2000. Alzheimer's is now the sixth leading cause of death in the United States. (See While there is no clear understanding of what starts the disease process, it is known that damage to the brain begins 10 to 20 years before any problems become evident.

While Alzheimer's disease is the most common form of dementia (50-70%), other forms of dementia include vascular dementia (also called multi-infarct dementia) , dementia with Lewy bodies (often called fronto-temporal dementia) , Pick's disease (often called fronto-temporal dementia) , alcohol-related dementia/Korsakoff's syndrome , infection related dementia: AIDS-related cognitive impairment , infection related dementia: Creutzfeldt-Jakob disease (CJD) , Parkinson's disease and Huntington's disease. While the different types of dementia affect different parts of the brain, they all have similar symptoms and behaviours. (Source:

Further information on the different forms of dementia is available from the Alzheimer's New Zealand website:

In New Zealand it is estimated that 41,000 people have dementia. This figure is expected to double by 2026 due to the increasing number of elderly people. It takes up to seven pairs of hands to care for every person with dementia. This means up to 300,000 people in New Zealand are currently affected by the disease. Alzheimer's New Zealand has recently launched a national dementia strategy and is urging the Government to make dementia a national health priority, following the example of Australia, Britain, South Korea and other countries. New Zealand Health Minister Mr Tony Ryall has called dementia the greatest challenge the New Zealand health service is going to face and has advised that district health boards and aged care providers are working to ensure adequate rest home care will be available. (See

The national dementia strategy developed by Alzheimer's New Zealand comprises eight strategic goals.

  1. Recognise dementia as a national health priority
  2. Increase public awareness of dementia
  3. Provide access to affordable and appropriate medication
  4. Improve early diagnosis and management of dementia
  5. Provide appropriate services to all people with dementia
  6. Provide support to family/whanau/carers of people with dementia
  7. Develop the workforce to deliver quality dementia care
  8. Increase dementia research and the evaluation of dementia practices

To date, the four drugs that have been approved for Alzheimer's disease treat only its symptoms. Now new guidelines have been proposed to diagnose signs of the disease in people not yet showing symptoms. There are also trials of new drugs underway that seek to slow the development of Alzheimer's by reducing the characteristic "amyloid" (plaque) accumulations that develop in the brains of people with Alzheimer's. The current thinking is that blocking the formation of amyloid may slow or stop the disease. However, there is no proof that this will make a difference; in 11 clinical trials just made public patients failed to show cognitive improvement even when their brains were cleared of plaque. (See

Some believe that even people with fairly mild symptoms may already have too much brain damage to be helped by the drugs. Thus some companies are seeking to start treatment early. However, if it turns out that preventing amyloid formation does not stop the progression of the disease then "millions of healthy people could end up taking something useless or even dangerous. And because it takes so long for Alzheimers to develop, it could be decades, if ever, before anyone knew the drug did not work." (See

The view that dementia is now a late stage in the process, and the change in the formal criteria for diagnosing Alzheimer's, will encourage a lot more testing in asymptomatic persons. While tests which reveal changes characteristic of Alzheimer's can allow patients and families to plan, there are ethical dilemmas associated with offering expensive biomarker tests if there is nothing that can be done to manage the disease. The tests also have consequences for lawyers, insurance companies and worker's compensation programs." (See