New Guidelines For Diagnosing Alzheimer's: Wishful Thinking... Dangerous Consequences
Previously, I have been quite critical of the DSM-5 suggestion to introduce a new diagnosis-- Minor Neurocognitive Disorder--on the grounds that it would create a large false positive problem and would lead to unnecessary worry and cost with no useful intervention.
New guidelines for the diagnosis of Alzheimer disease (AD) are being formulated by panels jointly sponsored by the National Institute on Aging and the Alzheimer’s Association. They were presented at the Alzheimer’s Association International Conference in Hawaii this past July and-unless opposed-might become official this fall. The guidelines have received extensive press coverage, most notably in upbeat articles by Gina Kolata1-3 in The New York Times suggesting that they represent an important breakthrough in the diagnosis of AD and might also further the efforts of drug companies to find an effective treatment.
The suggested guidelines would divide patients with AD into 3 groups of ascending severity and clarity of presentation:
• The first group is still preclinical (ie, it includes individuals who do not yet have any cognitive symptoms but who do have positive laborato-ry findings that might predict the development of AD).
• The second group has mild cognitive impairment and positive laboratory findings.
• The third group (and the only group in which AD is officially diagnosed) has classic dementia.
The guideline for the preclinical group recommends that laboratory tests be done only in research studies.
Originally, the guidelines for mild cognitive problems and dementia seemed to suggest that laboratory testing (with PET, MRI, or spinal taps) was ready, or soon would be ready, to be used in routine practice. Faced with widespread skepticism, the panels held a follow-up conference call to clarify their position and admitted that such testing is still only a research tool, not to be included in current clinical diagnosis. This makes great sense. All the available tests are in early stages of development and are not nearly ready for routine use.
Previously, I have been quite critical of the DSM-5 suggestion to introduce a new diagnosis-Minor Neurocognitive Disorder-on the grounds that it would create a large false-positive problem and would lead to unnecessary worry and cost with no useful intervention.4,5 The guidelines created by the joint panel of the National Institute on Aging and the Alzheimer’s Association are far more ambitious and far more dangerous than anything being considered for DSM-5. They would result in the widespread premature use of clinical laboratory testing well before the safety and utility of such testing is established. The proposals are the clearest possible example of narrowly focused experts getting far ahead of the available evidence and technology to suggest what will be an enormously costly public health experiment with potentially dire unintended consequences.
If we had well-established diagnostic tools to accurately identify preclinical and mild presentations of AD, the suggested guidelines would still carry risks but might make some sense. Unfortunately, however, the available laboratory tests are still in a very early stage of research development. Certainly they are promising and valued research tools, but none is near ready to be used in routine clinical practice-particularly in the general population of individuals with no symptoms or mild symptoms. Laboratory studies of AD are of recent vintage and have been tested only in small, select samples; they will probably have huge false-positive rates in the general population; and they are expensive and carry medical risks. Guidelines that promote premature, widespread, and expensive testing are ill-considered and reckless.
To make matters worse (and the suggested guidelines even more concerning and premature), there is no effective treatment or prevention for AD at any stage. So finding out that you are at increased risk for AD would provide little or no benefit-but would create needless worry, testing, treatment, expense, risk, and insurance and disability issues. All this is amplified by the fact that a large proportion of supposedly “at risk” individuals will have false-positive test results and will experience totally unnecessary worry, testing, and treatment.
The attempt to provide early identification with fallible tests and no effective treatment serves no useful purpose and can cause great harm not only to individuals but also to public health policy. Scarce health dollars should not be wasted on what would amount to a frivolous public health experiment. First, let’s do the research necessary to prove that the tests have clinical utility and to find medications that work. Then the guidelines will make sense.
How could such a really bad idea be forwarded by such renowned experts sponsored by such august organizations? I have in earlier pieces written on the tunnel vision of experts in any given area and their natural enthusiasm for pushing the boundaries of their disorder of interest. No doubt the premature emergence of these guidelines results from the great frustration we all feel at the slow pace of development of diagnostic and treatment tools for AD. Most of us expected a well-established laboratory test by now. Drug discovery has also been disappointingly slow. My guess is that the guideline makers hope to jump-start the field by highlighting the potential of early identification and the promise of newly developed research tools. But this is definitely putting the cart far, far before the horse. Guidelines that will have great influence on how people live their lives and how the country will spend limited health care dollars must follow well-established science and an inclusive public policy debate-not lead it.
I am convinced from my experience with experts that they act from naive good faith that expanding their field of interest will ultimately be good for patients. They tend to be surprisingly blind to the problems caused by false-positive misidentification and to societal costs because they are not trained to think in these terms (and not because of conflicts of interest as frequently alleged). But such naive goodwill does not permeate the corporations that market drugs and diagnostic tests. There will be an explosion of testing and treatment if these guidelines are approved, much (or all) of it unnecessary and expensive, some of it downright harmful. The medical/industrial complex will have another field day at the expense of medical and policy common sense.
The suggested guidelines for AD are not yet official-so there is still hope that concerted opposition can render them more realistic. Given the great impact they will have on public health policy, the guidelines should not become official until there is a wide public policy debate with input and monitoring that reaches beyond the narrow group of experts in the field. Decisions on AD are too important to patients and public policy to be made exclusively by experts on AD without consideration of the larger issues involved.
References:
References
1. Kolata G. New scan may spot Alzheimer’s. New York Times. July 12, 2010. http://www.nytimes.com/2010/07/13/health/research/13alzh.html?ref=health. Accessed July 29, 2010.
2. Kolata G. Rules seek to expand diagnosis of Alzheimer’s. New York Times. July 13, 2010. http://www.nytimes.com/2010/07/14/health/policy/14alzheimer.html?ref=health. Accessed July 29, 2010.
3. Kolata G. Finding suggests new aim for Alzheimer’s drugs. New York Times. September 1, 2010. http://www.nytimes.com/2010/09/02/health/research/02alzheimer.html?_r=1&ref=gina_kolata. Accessed October 11, 2010.
4. Frances A. Opening Pandora’s box: the 19 worst suggestions for DSM5. Psychiatr Times. 2010;27(3):9. http://www.psychiatrictimes.com/dsm/content/article/10168/1522341. Accessed July 29, 2010. 5. Frances A. It’s not too late to save “normal.” Los Angeles Times. March 1, 2010. http://articles.latimes.com/2010/mar/01/opinion/la-oe-frances1-2010mar01. Accessed July 28, 2010
