On November 16, the New York Times carried a report about the rapid spread of a new test which can identify Alzheimer’s Disease.
The test takes the form of a brain scan, in which a proprietary tracer is used to identify plaques – or, as the reporter puts it “barnaclelike clumps of protein, beta amyloid” – within the brain. These plaques indicate the presence of Alzheimer’s, a condition which is distinct from the underlying generic condition, dementia.
It is encouraging to learn that technology is advancing fast in analysis of a condition which was once thought to be impossible to diagnose with certainty in a living patient. But the central argument in the New York Times piece was that the capacity to identify Alzheimer’s is progressing far ahead of the ability to treat the disease.
That gives rise to a serious dilemma. What is gained by identifying a specific condition with a very poor prognosis, if there is no prospect of offering successful treatment?
There are also issues about ensuring that the tests are only interpreted by doctors properly trained in doing so – in the US 700 have so far qualified. As with other advances in diagnostic techniques, such as those for genetic susceptibility to breast cancer, there are huge implications in our growing capacity to identify people potentially vulnerable to specific illnesses. We have to consider the impact of such discoveries on those people. The questions include what will it mean in terms of getting employed and getting insured, quite apart from the impact on the individual’s overall state of mind. The dangers of misdiagnosis simply add to the complications.
The report notes that the test only came into the market in June this year but is now offered in some 300 US centres. It costs several thousand dollars, and is not yet covered by many US health insurers, nor by Medicare, the government programme which covers a substantial proportion of healthcare costs for most senior citizens in the US.
In the UK, therefore, we can safely assume that we are a long way from any possibility of such a test being offered routinely as part of NHS procedure. Despite that, improvements in diagnosis must surely be a necessary precursor to improvements in treatment, even if we would hope to see treatments developing at least as fast as diagnosis.