"Alzheimer's Disease" is the term used to describe a dementing disorder marked by certain brain changes, regardless of the age of onset. Alzheimer's disease is not a normal part of aging - - and it is not something that inevitable happens in later life. Rather, it is one of the dementing disorders, a group of brain diseases that lead to the loss of mental and physical functions. The disorder, whole cause is unknown, affects a small but significant percentage of older Americans. A very small minority of alzheimer's patients are under 50 years of age. However, most are over 65.

Alzheimer's disease is the exception, rather than the rule, in old age. Only 5 to 6 percent of older people are afflicted by alzheimer's disease or a related dementia - - but this means approximately 3 to 4 million Americans have one of these debilitating disorders. Research indicates that 1 percent of the population aged 65-75 has severe dementia, increasing to 7 percent of those aged 75-85 and to 25 percent of those 85 or older. As out population ages and the number of alzheimer's patients increases, costs of care will rise as well.

Although Alzheimer's disease is not yet curable or reversible, there are ways to alleviate symptoms and suffering and to assist families. And not every person with this illness must necessarily move to a nursing home. Many thousands of patients - - especially those in the early stages of the disease - - are cared for by their families in the community. Indeed, one of the most important aspects of medical management is family education and family support services. When, or whether, to transfer a patient to a nursing home is a decision to be carefully considered by the family.

The onset of Alzheimer's disease is usually very slow and gradual, seldom occurring before age 65. Over time, however, it follows a progressively more serious course. Among the symptoms that typically develop, none is unique to Alzheimer's disease at its various stages. It is therefore essential for suspicious changes to be thoroughly evaluated before they become inappropriately or negligently labeled Alzheimer's disease.

Problems of memory, particularly recent or short-term memory, are common early in the course of the disease. For example, the individual may, on repeated occasions, forget to turn off the iron or may not recall which of the morning's medicines were taken. Mild personality changes, such as less spontaneity or a sense of apathy and a tendency to withdraw from social interactions, may occur early in the illness. As the disease progresses, problems in abstract thinking or in intellectual functioning develop. You may notice the individual beginning to have trouble with figures when working on bills, with understanding what is being read, or with organizing the days work. Further disturbances in behavior and appearance may also be seen at this point, such as agitation, irritability, quarrelsomeness, and diminishing ability to dress appropriately.

The average course of the disease from the time it is recognized to death is about 6 to 8 years, but it may range from under 2 years to over 20 years. Those who develop the disorder later in life may die from other illnesses (such as heart disease) before Alzheimer's disease reaches its final and most serious stage.

The reaction of an individual to the illness and the way he or she copes with it also varies and may depend on such factors as lifelong personality patterns and the nature and severity of the stress in the immediate environment.

As research on Alzheimer's disease continues, scientists are now describing other abnormal chemical changes associated with the disease. These include nerve cell degeneration in certain areas of the brain. Also, defects in certain blood vessels supplying blood to the brain have been studied as a possible contributing factor.

There is no way at the present time to determine who may get Alzheimer's disease. The main risk factor for the disease is increased age. The rates of the disease increase markedly with advancing age, with 25 percent of people over 85 suffering from Alzheimer's or other sever dementia.

Other things often noticeable may be depression, severe uneasiness, and paranoia or delusions that accompany or result from the disease, but they can often be alleviated by appropriate treatments.

Alzheimer's disease has emerged as one of the great mysteries in modern day medicine, with a growing number of clues but still no answers as to its cause. Researchers have come up with a number of theories about the cause of this disease but so far the mystery remains unresolved.

Because of the many other disorders that are often confused with Alzheimer's disease, a comprehensive clinical evaluation is essential to arrive at a correct diagnosis of any symptoms that look similar to those of Alzheimer's disease. In most cases, the family physician can be consulted about the best way to get the necessary examinations.

Stress on the family can take a toll on both the patient and the caregiver alike. Caregivers are usually family members - - either spouses or children - - and usually wives and daughters. As time passes and the burden mounts, it not only places the mental health of family caregivers at risk. It also diminishes their ability to provide care to the diseased patient. Hence, assistance to the family as a whole must be considered.

As the disease progresses, families experience increasing anxiety and pain at seeing unsettling changes in a loved one, and they commonly feel guilt over not being able to do enough. The prevalence of reactive depression among family members in this situation is disturbingly high - - caregivers are chronically stressed and are much more likely to suffer from depression than the average person. If caregivers have been forced to retire from positions outside the home. They feel progressively more isolated and no longer productive members of society.

The likelihood, intensity, and duration of depression among caregivers can all be lowered through available interventions. For example, to the extent that family members can offer emotional support to each other and perhaps seek professional consultation, they will be better prepared to help their loved one manage the illness and to recognize the limits of what they themselves can reasonably do.

Though Alzheimer's disease cannot at present be cured, reversed, or stopped in its progression, much can be done to help both the patient and the family live through the course of the illness with greater dignity and less discomfort. Toward this goal, appropriate clinical interventions and community services should be vigorously sought.

While Alzheimer's disease remains a mystery, with its cause and cure not yet found, there is considerable excitement and hope about new findings that are unfolding in numerous research settings. The connecting pieces to the puzzle called Alzheimer's disease continue to be found.