Early diagnosis of Alzheimer's disease (AD) is critical because that's when currently available treatments work best. But most people don't get diagnosed until the disease is in more advanced stages.

Medinteract (Knoxville, Tennessee) has developed a 10-minute test called the ALZselftest that costs $20 which produces results with 95% accuracy.

"It seems clear that early diagnosis is the key," neurologist John Dougherty, founder of Medinteract, told Medical Device Daily. "Alzheimer's begins 10 to 20 years prior to the onset of clinical symptoms. Early treatment can be effective in slowing the disease down.

"Unfortunately, 60% of people with early signs of the disease go undiagnosed until they are past the early stages, when treatment options are best. Our goal was to make low-cost screening available to the general public so they can monitor their cognitive health, just as they would monitor blood pressure or blood sugar levels."

The National Institute on Aging reports that there are currently four FDA-approved drugs available treat Alzheimer's. For people with mild or moderate disease, donepezil (Aricept), rivastigmine (Exelon) or galantamine (Razadyne) may help maintain cognitive abilities and help control certain behavioral symptoms for a few months to a few years.

Donepezil can be used for patients with severe AD. Memantine (Namenda) also is used to treat moderate to severe Alzheimer's. None of these therapies, however, change the underlying disease process.

But these drugs treat the symptoms. Dougherty said that there are things people can do if they discover early that they are headed for cognitive decline.

"One of the most important aspects of delaying the onset is increased mental and physical activity," he said. "If we can get people active, both physically and mentally, and treat them and you might be able to delay the onset or reduce the severity."

The National Institute on Aging estimates that 4.5 million Americans currently suffer from Alzheimer's disease, and that number will continue to rise as "baby boomers" become older.

Dougherty, who also is medical director of the Cole Neuroscience Center at the University of Tennessee Medical Center, (Knoxville), developed a test delivered on paper in 2002, but has now adapted it for computer use and is making it available to people online.

The ALZselftest provides scoring information and a report, which people can take to their physician's office for further evaluation. For those uncomfortable with their computer skills, the test has audible directions or can be taken with the aid of a friend or family member.

Ongoing clinical studies of the ALZselftest show it is 98% accurate in distinguishing those with cognitive impairment from non-impaired persons. This rate is achieved because ALZselftest measures all of the cognitive domains.

It also has shown 95% accuracy at distinguishing between the stages of Alzheimer's, including mild cognitive impairment. By contrast, the widely used screening test, Mini-Mental States Exam (MMSE), reaches 67% diagnostic accuracy, according to Medinteract.

Dougherty currently works with about 1,500 Alzheimer's patients and 250 of those participated in a study of the ALZselftest. "We found that, in terms of making a general diagnosis of dementia, the MMSE is not so bad. It's 83% accurate, but our test is 97% accurate. In determining the degree and nature of the cognitive problem, our self-test is 95% accurate in classifying patients and the MMSE is 67%."

He added, "The ALZselftest will produce results that are normal, mild cognitive impairment, early, moderate or severe Alzheimer's disease. Our test is much more precise."

Although the ALZselftest can test for Alzheimer's, Dougherty is quick to point out that no test can diagnose the disease. "You need an appropriate examination. We recommend [patients] take it to their general physician for an appropriate evaluation. The important thing to remember in the general medical population is that 60% of patients go undiagnosed because their general physician may not be trained in this or have time to do cognitive tests."

"If early treatment is helpful for Alzheimer's disease, we've got to retool ourselves to make an earlier diagnosis," he said.

Dougherty is marketing the online test both to physicians and directly to consumers.