It is important to keep in mind, however, that the 7 Minute Screen does not provide a certain diagnosis of Alzheimer's disease. As a quick screening test, it only identifies people with impairments in memory, reasoning, and other mental tasks that may be due to dementia. To get a true diagnosis, the person must take a longer, more sophisticated physical and mental exam.
In designing the 7 Minute Screen, Solomon made improvements to four pre-existing psychological tests so that they would be more sensitive for detecting dementia. The tests zero in on tasks that are more challenging for people with Alzheimer's disease than for people with normal age-related memory loss. For example, one test asks the patient to recall items from a list of 16 pictures, based in part on hints provided by the tester. People with Alzheimer's even in its early stages still have trouble recalling the items, since they were not stored properly in the first place. This means the test can tell the difference between dementia and age-related memory loss.
Ultimately, Solomon would like to see primary care physicians include an Alzheimer's screening test in routine check-ups for seniors. He says the results of an Alzheimer's screen should be thought of as just like any other medical information a doctor needs to know, like blood pressure or cholesterol level. Regardless of whoever administers the screen, he emphasizes, a physician must carefully explain to the patient that the test only establishes the likelihood of dementia, and is not a certain diagnosis.
Since the 7 Minute Screen is not a complete exam, it is not 100 percent accurate. To date, Solomon has results from the testing of about 1,800 people who have taken the 7 Minute Screen. Overall, about 90 percent of people who score high on the screen are diagnosed with dementia in a follow-up exam.
Importantly, Solomon says, one of his most recent studies evaluated the accuracy of the screen in a real-world setting: a doctor's office. The study, in which the 7 Minute Screen was administered to 137 patients in a physician's office, accurately predicted dementia in 91 percent of those tested. The other 9 percent "failed" the screen but were not subsequently diagnosed with dementia. The reasons for this are not thoroughly understood yet, Solomon explains, but a person can fail the screen because of things such as depression or grogginess from medications.
The 7 Minute Screen is not the only Alzheimer's screening tool in the works. Solomon says there are about ten others under development in various research labs. But the 7 Minute Screen is one of the first in the field thanks in part to financial support from the Janssen Research Foundation in Titusville, New Jersey. Janssen is a pharmaceutical firm currently developing a new Alzheimer's drug called galantamine. To help doctors identify people who might benefit from Alzheimer's drugs, Janssen is distributing the screen to physicians free of charge. Janssen has already given away 6,700 kits in the United States, and receives more than 500 new requests per month.
Solomon's work on the screen is part of a much larger effort to develop ways to detect Alzheimer's early. Some researchers, for instance, hope to use brain scanning technology such as magnetic resonance imaging (MRI) to identify subtle damage to the brain before impairments in thinking show up. Other approaches look for gene abnormalities that some studies have linked to Alzheimer's.
The variety of Alzheimer's tests on the horizon makes it important to thoroughly evaluate the 7 Minute Screen, according Dr. Zaven Khachaturian, former head of the Neurobiology of Aging research program at the National Institutes of Health and now an independent consultant on Alzheimer's research with KRA, Inc. in Maryland. "Clearly a screen has a value," Khachaturian says. "But the user needs to know how well it works."
He likens the process of evaluating a new medical test to performance testing on new cars. Consumers need to know about gas mileage and acceleration to make an informed choice. Similarly, physicians need to know how well an Alzheimer's screen performs under various conditions. For example, one screen may turn out to catch Alzheimer's earlier in people under 65; another may perform better in people over 70.
"The important thing is to have the very best for the patients," Khachaturian says. "It may turn out that it will be a combination of tests. But they all need to run through the same process before they can be accepted by the medical community." Solomon agrees. "The more the merrier," he says. "If they use ours, that's great. The key thing is to get people screened."
Indeed, once dementia takes hold, brain cells and the memories they encode begin to die, and are lost forever. The ultimate hope, of course, is to find a way to prevent Alzheimer's disease altogether. But if the day comes that we learn how to at least halt the progression of dementia, early detection will be critical to minimizing the cruel and costly impact of the illness on individuals, families and society.