There are new hopes for a simple blood test to diagnose Alzheimer's.
It's hoped to provide answers for patients who want to know if they have the disease, and it could help speed up research for treatments.
But it also creates a dilemma, would you really want to know?
Scientists in Sweden say the blood test is as accurate as brain scans and some spinal tests in diagnosing Alzheimer's.
Specialist equipment is used to measure a variant of a protein called tau.
"Tau is a protein that we believe is one of the main culprits that cause Alzheimer's disease and the big breakthrough now is that we're able to measure this tau variant in blood in a very reliable fashion," says lead author Oskar Hansson, Professor of Clinical Memory Research, Lund University.
Alzheimer's NZ chief executive Catherine Hall says a diagnosis is useful because people often want to know if there really is something wrong with them.
"But what would be really useful is to be able to get a diagnosis easily and then to get the services and support that you need to be able to live your best possible life," she says.
Around 70,000 New Zealanders have dementia and it is massively on the rise. Alzheimer's disease is the most common form of dementia, making up two-thirds of cases.
This test can identify the disease as much as 20 years in advance. The question is, would you want to know you have a disease that currently has no cure.
Its creators say it would mainly be used for those with symptoms.
"I don't think this blood test should be used for screening of healthy individuals and the reason is that we don't have any therapy today that stops or slows down the disease in healthy individuals," says Prof Hansson.
As well as getting those with the disease the help they need, scientists also hope the test will reduce misdiagnosis.
"That is as problematic I think because then you envision that you will become demented in a few years, and so on, which is not the case."
Dementia New Zealand says research has shown that the following things decrease the risk of getting Alzheimer's Disease:
- Physical activity
- Social activity avoid loneliness
- Mental activity- try new and challenging intellectual activities
- Stopping smoking
- Managing blood pressure, cholesterol, blood sugar and weight
- Good food choices: Mediterranean diet
- Protect your head
- Reduce stress