Alzheimer's Disease

Alzheimer's (ALTZ-hy-merz) disease is an incurable condition in which abnormal plaques and tangles form in the brain, accumulating over time and interfering with nerve cell connections. The disease leads to problems with memory and thinking and to changes in personality and behavior, generally called dementia (de-MEN-sha).

Joey's Story

Joey's grandmother does the strangest things. She tells the same stories over and over and often forgets words for common objects, such as television and fork. She puts her purse in the refrigerator and sometimes comes to dinner wearing her dress turned inside out. But what is most troublesome to Joey is that she often does not recognize him or his mom.

At first, the family simply thought his grandmother was getting old. She is in her 80s, and his mother told him that sometimes older people have trouble remembering things. But as his grandmother's forgetfulness and odd behavior became worse, the family realized it was more than just an occasional lapse in memory, which happens to everyone once in a while.

Joey's grandmother is one of the 5.1 million Americans who have Alzheimer's disease.

What Is Alzheimer's Disease?

Alzheimer's disease is a neurological * disorder in which structures called plaques and tangles form in the cerebral (se-REE-bral) cortex (KORteks), the outer surface of the brain, as well as in the brain matter just under the cortex. The cortex has several functional areas, including those involved with vision, hearing, speech, understanding, and bodily awareness. Plaques and tangles interfere with the normal functioning of the neurons (NOO-rahnz), or nerve cells, and the transmission of messages between the brain and other parts of the body. Although these structures occur to some extent with normal aging, they are much more prevalent in people who have Alzheimer's disease.

Alzheimer's disease is the most common form of dementia * . Autopsies * reveal the following abnormalities in the brains of people with Alzheimer's:

Alzheimer's disease is not a normal part of aging.

History of Alzheimer's Disease

As Alois Alzheimer (1864–1915), a German psychiatrist, peered into his microscope, he was puzzled by what he saw. The slides of the brain of his 51-year-old patient, Auguste D., contained deposits and tangles that looked like a mass of threads. He had worked with Auguste D. at the asylum in Frankfurt-am-Main and was amazed by her bizarre behavior. In 1907, he wrote these words:

The woman showed as her first symptom a jealousy toward her husband. Soon she showed a rapidly increasing amnesia; she became lost in her own apartment, carried objects about aimlessly, hid them, sometimes believed she was to be murdered, and had spells of unrestrained screaming…. The autopsy showed a diffusely atrophied brain … remarkable changes of the neurofibrillae. In place of a normal cell, one or several fibrillae, which ran parallel to each other, were altered in a similar fashion…. Apparently, we are dealing with an unidentified illness.

He did not know that his friend Emil Kraepelin (1856–1926) would refer to the condition as Alzheimer's disease in a journal article in 1911. The name stuck.

The disease received little attention until the late 1970s, when several factors merged:

Normal brain on the left and the brain of a person with Alzheimer's disease on the right, which is atrophied and shows a loss of cortex and white matter.

Normal brain on the left and the brain of a person with Alzheimer's disease on the right, which is atrophied and shows a loss of cortex and white matter.
Jessica Wilson/Science Source.

What Causes Alzheimer's Disease?

In the early 2000s, scientists did not fully understand what causes Alzheimer's disease, while they suspected several factors may play a role. Age is the most important risk factor; the number of people with the disease doubles every five years beyond the age of 65 years.

Family history is another risk factor. Individuals with a first-degree relative, such as a parent or sibling, with dementia have as much as a 30 percent increased risk of developing the disease. Risk for individuals with two or more siblings affected with the disorder increases by three times more than someone who has no family history of the disease. Genes * seem to play a role in certain Alzheimer's cases. Studies have suggested that genes are associated with both the common form of Alzheimer's disease, which affects many people and generally begins over 65 years of age, with increasing frequency as people age; and with a rare form of the disease having an early onset between the ages of 30 and 60 years. At least five genes might be implicated in the early-onset form, which runs in families and is inherited.

How Is Alzheimer's Disease Diagnosed?

Alzheimer's is difficult to distinguish from other mental health problems. Doctors usually begin by taking a medical history and doing a physical examination to make sure some other condition or other type of dementia is not causing the memory and behavior problems. Many diseases and conditions can cause symptoms similar to those of Alzheimer's. Some, such as vitamin deficiencies, can be corrected easily; others can be treated with prescription drugs.

In November 1994, former President Ronald Reagan, who was suffering from Alzheimer's disease, said farewell to the nation in a letter:

I have recently been told that I am one of the millions of Americans with Alzheimer's disease. Nancy and I had to decide whether we would keep this matter to ourselves as private citizens or would make it known. We had the feeling that it was important to announce this message publicly.

This letter had a great effect. Alzheimer's disease became widely recognized, and research dollars funded studies into its cause and the search for a cure.

Doctors also administer various verbal and written tests to assess how well the person's brain is functioning. They interview the person and family members about recent events, looking for examples of the symptoms. If a person is younger than 60 years of age, a genetic test might be ordered because most cases of Alzheimer's disease in people who are between 40 and 59 years of age are linked to the presence of certain genes that can be identified. Sometimes doctors look for signs of a stroke or abnormal areas in the brain, using x-rays or other high-technology equipment that allows them to see inside the body, such as magnetic resonance imaging * (MRI). With this sophisticated equipment and testing, accuracy of diagnosis is about 85 to 90 percent.

Once other possible causes of the symptoms have been ruled out, doctors begin to suspect that a person has Alzheimer's disease. If the symptoms worsen with time and no other explanation can be found, doctors say the person has Alzheimer's. But diagnosis can be absolutely confirmed only by direct examination of brain tissue during an autopsy. Doctors look for plaques and fibers, which look like small tangled spiral staircases.

Additional diagnostic methods being investigated include:

How Is Alzheimer's Disease Treated?

Several drugs help relieve some symptoms in some people. These drugs do not cure the disease but may slow its progression. The drugs donepezil (Aricept), rivastigmine (Excelon), and galantamine (Razadyne) may help symptoms for a limited time. Memantine (Namenda) is sometimes used for moderate to severe Alzheimer's cases. A combination drug containing donepezil and memantine (Namzaric) has been developed to help manage moderate to severe symptoms of the disease. Some medicines may help control behavioral symptoms such as sleeplessness, agitation, wandering, anxiety, and depression. The relief is not permanent, and the drugs do not work for everyone.

Once-Promising Treatments That Have Been Discredited

In the search for a cure, scientists looked at many possibilities. Most of the emphasis on developing new drugs to treat Alzheimer's has been focused on stopping, slowing, or treating the amyloid plaques in the brain. Most drugs, which showed promising results in mice in laboratory studies, have not shown the same effectiveness in humans.

Since the year 2000, over 200 drugs have been tested and approved for use in the treatment of Alzheimer's. More than 200 drugs have been studied, most of them for alleviating symptoms. After years of investigation researchers found that a chosen treatment did not work. Substances that once were seen as promising but were later shown not to be include the following:

Did You Know?

Burden of Care or Issues for Caregivers

Caring for someone with Alzheimer's disease can be very stressful, particularly in the later stages of the disorder. Declines in mental and physical functioning are hallmarks of this disease. Patients in later stages typically are not able to care for their own personal needs such as bathing or grooming and may no longer be able to use the bathroom on their own. They need help with simple tasks such as eating and drinking and, eventually, may be unable to swallow.

Relationships change. People with Alzheimer's may not recognize members of their immediate families such as their spouse or children. In most instances there are behavioral changes such as aggression, anger, anxiety, depression, confusion, and loss of memory.

There are many sleep issues which affect individuals with Alzheimer's including increases in wandering and behavior changes, which begin at dusk, known as sundowning, and which last through the night. This behavior, which can occur night after night even with medication, can wreak havoc on family caregivers.

Often, the needs of patients with Alzheimer's, particularly those in the mid- and later stages of the disease, overwhelm family caregivers. When that happens the patient is usually placed in a nursing home or other group care facility that employs specialized staff trained in the care of patients with dementia or other memory issues.

What Does the Future Hold?

Scientists are working hard to develop effective therapies. New drugs are being developed that are designed to treat the symptoms and target genetic pathways of the disease. Breakthroughs in drug research may revolutionize the way brain diseases are treated and prevented. Approaches under consideration include the following:

See also Aging • Chronic Illness • Dementia • Diabetes • Elder Abuse • Heart Disease: Overview • Hyperlipidemias • Hypertension • Memory and Amnesia • Obesity


Books and Articles

O'Brien, Greg. On Pluto: Inside the Mind of Alzheimer's. Brewster, MA: Codfish Press, 2014.

Osenga, Joshua. Forget Me Not: Living with Alzheimer's Disease. Durham, NC: Bull City, 2014.

Spinney, Laura. “Alzheimer's Disease: The Forgetting Gene.” Nature. June 4, 2014. (accessed March 13, 2016).


Kim, Steven. “Best Alzheimer's Videos of 2015.” . (accessed March 13, 2016).


Alzheimer's Association. 225 N. Michigan Ave., 17th Floor, Chicago, IL 60601. Toll-free: 800-272-3900. Website: (accessed March 13, 2016).

Alzheimer's Disease Education and Referral Center. 31 Center Dr., Building 31, Room 5C27, MSC 2292, Bethesda, MD 20892. Tollfree: 800-438-4380. (accessed March 13, 2016).

* neurological (nur-a-LAH-je-kal) refers to the nervous system, which includes the brain, spinal cord, and the nerves that control the senses, movement, and organ functions throughout the body.

* dementia (dih-MEN-sha) is a loss of mental abilities, including memory, understanding, and judgment.

* autopsy (AW-top-see) is an examination of a body after death to look for the cause of death or the effects of a disease.

* cerebral cortex (suh-REE-brul KIR-teks) is the part of the brain that controls functions such as conscious thought, listening, and speaking.

* neurotransmitter (NUR-o-tranz-mit- er) is a chemical substance that transmits nerve impulses, or messages, throughout the brain and nervous system and is involved in the control of thought, movement, and other body functions.

* neurologist (new-RHAL-eh-jist) is a physician who specializes in diagnosing and treating diseases of the nervous system.

* genes (JEENS) are chemical structures composed of deoxyribonucleic acid (DNA) that help determine a person's body structure and physical characteristics. Inherited from a person's parents, genes are contained in the chromosomes found in the body's cells.

* magnetic resonance imaging or MRI uses magnetic waves, instead of x-rays, to scan the body and produce detailed pictures of the body's structures.

* spinal tap also called a lumbar puncture, is a medical procedure in which a needle is used to withdraw a sample of the fluid surrounding the spinal cord and brain. The fluid is then tested, usually to detect signs of infection, such as meningitis, or other diseases.

* stem cell an unspecialized cell that gives rise to differentiated cells.

Disclaimer:   This information is not a tool for self-diagnosis or a substitute for professional care.

(MLA 8th Edition)