There is a single question that may accurately and reliably differentiate between dementia and normal aging. Not only is this question potentially able to discriminate between normal senility and dementia, it may prove a powerful method to differentiate Alzheimer’s Disease from other types of dementia.
Here is the question. How is your memory?
Perhaps this appears too simple to be elegant. As with any rule to describe complex phenomenon, the rule only has power within specific boundaries. For example, Newtonian physics is so powerful that it largely accounts for the success of NASA’s space program. Newtonian physics loses most of its predictive power when the object is going very fast, or is very small. This in no way renders Isaac Newton’s mechanics useless, rather his worldly physics is extremely useful within certain parameters. If the observer loses sight of these parameters, then the power of the system may suffer. A rule that holds true for all phenomenon is compelling, but it may come at the expense of explaining anything in the particular.
The boundaries that are important for this rule are predicated on the functioning of the person before dementia is suspected. When a person is questioned regarding the status of their memory, this directly calls upon their level of self-awareness. The awareness of self appears to be well correlated to intelligence, but again within specific parameters. If one questions a person with mild mental retardation regarding a cognitive skill, they will likely have some idea of the meaning, but their responses will not be very accurate in relation to informants. Questioning someone with moderate mental retardation will reveal that they do not understand abstract concepts regarding cognition. Once low average intelligence is reached, self-awareness is typically functional. There is a lack of evidence indicating that self-awareness increases with above average intelligence. It may increase, but research that converges on this conclusion is lacking. A general rule offered is that self-awareness is likely normal until intelligence falls below the average range. As with any cognitive skill, self-awareness may be significantly greater or lesser than one’s Full Scale IQ, but it will likely be well correlated across thousands of individuals.
The other boundary that needs to be considered is age. It is unlikely that this question has much utility before the age of 75. Purely as an artifact of testing thousands of patients, it is rare for someone before the age of 70 to complain about their memory. By the age of 80, most non-demented patients of average intelligence complain about their memory. People in their 80’s are self-aware that their memory has declined, which is realistic and insightful. The ability to name common objects and freely recall verbal information starts to decline in our 50’s, and is very evident to ourselves and others by the late 70’s. In addition, people who age well are typically irritated by their inability to recall and generate names for people and objects. Even in the early stages of a senile dementia, the victim is not bothered by their poor performance, and they frequently generate external causes for their inability to name or recall.
The next time you speak with someone in their 80’s who is constantly bemoaning their memory, let them know their cognition is likely just fine! Conversely, the next aged person with whom you speak reporting an excellent memory should be a cause for concern. If this person is college educated and held a middle-class job, then be very concerned. If the person is suspected to be below average in terms of education and vocation, then the answer to this question is less revealing. Also remember that this question is less able to discriminate between normal aging and Alzheimer’s in those younger than 75. There are many causes of poor verbal memory throughout our lifespan, but the early degradation of self-awareness is nearly unique to Alzheimer’s Disease. This is likely the source of the question’s utility and power.
Whether it is termed the “dementia question” or the “Holzmacher paradigm” is less important than future research into the uses of this questions for clinical practice. This single brief question may offer physicians a procedure to accurately make dementia referrals, as well as provide a simple way for caretakers to make treatment decisions. The greatest difficulty with the question is that it appears too simplistic to be meaningful, let alone useful. Perhaps Friar Ockham was correct, amongst competing explanations, the simplest solutions are most satisfactory. If anyone knows of a simpler method to reliably differentiate between normal aging and Alzheimer’s Disease, please write as soon as possible. It is hoped that clinicians will weigh in on this proposal, as my razor may have removed a bit too much. As always, comments from any interested party are welcome.