Alzheimer’s (AHLZ-high-merz) disease is a progressive brain disorder that gradually destroys a person’s memory and ability to learn, reason, make judgments, communicate and carry out daily activities. As Alzheimer’s progresses, individuals may also experience changes in personality and behavior, such as anxiety, suspiciousness or agitation, as well as delusions or hallucinations.
In late stages of the disease, individuals need help with dressing, personal hygiene, eating and other basic functions. People with Alzheimer’s die an average of eight years after first experiencing symptoms, but the duration of the disease can vary from three to 20 years.
Although there is currently no cure for Alzheimer’s, new treatments are on the horizon as a result of accelerating insight into the biology of the disease. Research has also shown that effective care and support can improve quality of life for individuals and their caregivers over the course of the disease from diagnosis to the end of life.
Causes of Alzheimer’s Disease
Alzheimer’s disease has no known single cause, but in the last 15 years scientists have learned a great deal about factors that may play a role.
Late-onset Alzheimer’s, which chiefly affects individuals over age 65, is the more common form of the illness that is most often associated with the term “Alzheimer’s disease.” The greatest known risk factors for late-onset Alzheimer’s are increasing age and a family history of the disease. The likelihood of developing late-onset Alzheimer’s approximately doubles every five years after age 65. By age 85, the risk reaches nearly 50 percent. Scientists have so far discovered one gene that increases risk for late-onset disease.
Rare, familial types of Alzheimer’s found in a few hundred families worldwide have been linked to specific genes.
Individuals who inherit these genes are virtually certain to develop the disease, usually before age 65, and sometimes as early as their 30s or 40s.
Researchers are working to discover other factors that affect Alzheimer risk. Some of the most exciting preliminary evidence suggests that strategies for general healthy aging may also help reduce the risk of developing Alzheimer’s. These measures include controlling blood pressure, weight and cholesterol levels; exercising both body and mind; and staying socially active.