The case for early diagnosis of Alzheimer's disease

The five medications approved by the Food and Drug Administration for the treatment of Alzheimer's have not been shown to slow the disease's progress. What, then, is the purpose of seeking an early diagnosis -- except to destroy one's peace of mind?

There are several good reasons, say Alzheimer's experts. They say that the drugs do, for many, decrease the severity of symptoms and, for a limited time, mask the progressive loss of mental function. That can translate into more time to get your affairs in order, a few more months of being able to live independently and line up help and a bit more time for meaningful family visits.

It is also true that responses to the drugs approved for Alzheimer's disease vary widely from patient to patient, says Dr. William H. Thies, vice president of medical and scientific relations for the Alzheimer's Assn.

For some, the medications appear to hold off cognitive deterioration very well for a long time; for other patients, they don't. If you're a good responder -- and you won't know until you try them -- you could hold steady at a point of higher function and gain a lot of extra time.

There's also new evidence that the drugs may work better at slowing the disease's progress when they are used longer, and in combination. A study published in summer in the journal Alzheimer's Disease and Associated Disorders followed 378 patients for at least 2 1/2 years and found that those who had been on the drugs longest -- and who took more than one medication for the condition -- had the slowest rates of progression of cognitive decline.

Thies also says that an early diagnosis can make the changes that come with Alzheimer's disease easier for a patient's family. Erratic behavior, irritability and loss of function are easier to cope with when understood as symptoms of a disease. "Many think this is some kind of unmasking of some underlying personality trait," Thies says. "It's not that Uncle Charlie is changing or behaving badly; it's that Uncle Charlie is sick and this is the way his illness manifests itself."

Thies also notes that a diagnosis is generally the only entree to clinical trials, which for many patients are a way to secure excellent care and to gain access to experimental therapies -- of which there are 14 in late-stage clinical trials. By their participation in studies, patients diagnosed early can give researchers new insights into the progression of the disease, which has until recently only been recognized late; those insights could lead to new drugs and new interventions that could alter the course of Alzheimer's disease. "If you are a person who's oriented to giving back to society, you'll miss that opportunity" if you delay diagnosis, Thies says.

Finally, new diagnostic tests, greater knowledge and more public awareness of dementia's symptoms are making early diagnosis more possible. A clinician who is experienced in diagnosing Alzheimer's disease can generally do so with confidence in about nine out of 10 cases, even when symptoms are newly recognized, experts say.

-- Melissa Healy