In Alzheimer’s disease, as in other types of dementia, increasing numbers of nerve cells deteriorate and die. A healthy adult brain has 100 billion nerve cells, or neurons, with long branching extensions connected at 100 trillion points. At these connections, called synapses, information flows in tiny chemical pulses released by one neuron and taken up by the receiving cell. Different strengths and patterns of signals move constantly through the brain’s circuits, creating the cellular basis of memories, thoughts and skills.

In Alzheimer’s disease, information transfer at the synapses begins to fail, the number of synapses declines and eventually cells die. Brains with advanced Alzheimer’s show dramatic shrinkage from cell loss and widespread debris from dead and dying neurons.

SYMPTOMS

Alzheimer’s disease can affect different people in different ways, but the most common symptom pattern begins with gradually worsening difficulty in remembering new information. This is because disruption of brain cells usually begins in regions involved in forming new memories. As damage spreads, individuals experience other difficulties. The following are warning signs of Alzheimer’s:

• Memory loss that disrupts daily life
• Challenges in planning or solving problems
• Difficulty completing familiar tasks at home, at work or at leisure
• Confusion with time or place
• Trouble understanding visual images and spatial relationships
• New problems with words in speaking or writing
• Misplacing things and losing the ability to retrace steps
• Decreased or poor judgment
• Withdrawal from work or social activities
• Changes in mood and personality

For more information about the warning signs of Alzheimer’s, visit Alzheimer's Association.

TREATMENT AND PREVENTION

No treatment is available to slow or stop the deterioration of brain cells in Alzheimer’s disease. The U.S. Food and Drug Administration has approved five drugs that temporarily slow worsening of symptoms for about six to 12 months, on average, for about half of the individuals who take them.

Despite the current lack of disease-modifying therapies, studies have consistently shown that active medical management of Alzheimer’s and other dementias can significantly improve quality of life through all stages of the disease for diagnosed individuals and their caregivers. Active management includes appropriate use of available treatment options, effective integration of coexisting conditions into the treatment plan, coordination of care among physicians and others involved in maximizing quality of life for people with Alzheimer’s or other dementia and use of such supportive services as counseling, activity and support groups and adult day center programs.

A growing body of evidence suggests that the health of the brain - one of the body’s most highly vascular organs - is closely linked to the overall health of the heart and blood vessels. Some data indicate that management of cardiovascular risk factors, such as high cholesterol, Type 2 diabetes, high blood pressure, smoking, obesity and physical inactivity may help avoid or delay cognitive decline. Many of these risk factors are modifiable - that is, they can be changed to decrease the likelihood of developing both cardiovascular disease and the cognitive decline associated with Alzheimer’s and other forms of dementia. More limited data suggest that a low-fat diet rich in fruits and vegetables may support brain health, as may a robust social network and a lifetime of intellectual curiosity and mental stimulation.

PREVALENCE

An estimated 5.3 million Americans of all ages have Alzheimer’s disease. This figure includes 5.1 million people aged 65 and older and 200,000 individuals under age 65 who have younger-onset Alzheimer’s. The Alzheimer’s Association estimates that there are 500,000 Americans younger than 65 with Alzheimer’s and other dementias. Of these, approximately 40 percent are estimated to have Alzheimer’s.

• One in eight people aged 65 and older (13 percent) have Alzheimer’s disease.
• Every 70 seconds, someone in America develops Alzheimer’s. By mid-century, someone will develop the disease every 33 seconds.

LOOKING TO THE FUTURE

The number of Americans surviving into their 80s and 90s and beyond is expected to grow dramatically due to advances in medicine and medical technology, as well as social and environmental conditions. Since the incidence and prevalence of Alzheimer’s disease and other dementias increase with age, the number of people with these conditions will also grow rapidly.

• In 2000, there were an estimated 411,000 new (incident) cases of Alzheimer’s disease. For 2010, that number is projected to be 454,000 new cases; by 2030, 615,000; and by 2050, 959,000.
• This year, more than an estimated 5.5 million Americans are 85 years and older; by 2050, that number will nearly quadruple to 19 million.
• While the number of Americans aged 100 years and older is estimated at 80,000 in 2010, by 2050 there will be more than a half million Americans aged 100 years and older.
• The 85-years-and-older population currently includes about 2.4 million people with Alzheimer’s disease, or 47 percent of the Alzheimer population aged 65 and over. When the first wave of baby boomers reaches age 85 years (2031), an estimated 3.5 million people aged 85 and older will have Alzheimer’s.
• The number of people aged 65 and older with Alzheimer’s disease is estimated to reach 7.7 million in 2030 - more than a 50 percent increase from the 5.1 million aged 65 and older currently affected.
• By 2050, the number of individuals aged 65 and older with Alzheimer’s is projected to number between 11 million and 16 million - unless medical breakthroughs identify ways to prevent or more effectively treat the disease. Barring such developments, by 2050 more than 60 percent of people with Alzheimer’s disease will be aged 85 or older.

MORTALITY

While other major causes of death continue to experience significant declines, those from Alzheimer’s disease have continued to rise. In 1991, only 14,112 death certificates recorded Alzheimer’s disease as the underlying cause. Comparing changes in selected causes of death between final data for 2000 and final data for 2006 deaths attributed to Alzheimer’s disease increased 46.1 percent, while those attributed to the number one cause of death, heart disease, decreased 11.1 percent.

Patterns of reporting deaths on death certificates change substantially over time, however, for Alzheimer’s and for other causes of death. Alzheimer’s is a major cause of death and is clearly becoming a more common cause as the populations of the United States and other countries age. The increase in the number and proportion of death certificates listing Alzheimer’s may strongly reflect both changes in patterns of reporting deaths on death certificates as well as an increase in the actual number of deaths attributable to Alzheimer’s.

CAREGIVING

Paid Caregiving

Older Americans represent approximately 12 percent of the population. However, they comprise 26 percent of physician office visits, approximately a third of all hospital stays, a third of all prescriptions, nearly 40 percent of all emergency medical responses and 90 percent of nursing home residents, according to the National Academy of Sciences. Alzheimer’s disease will clearly require a significant portion of future healthcare workforce.

Family Caregiving

Almost 11 million Americans provide unpaid care for a person with Alzheimer’s disease or another dementia. These unpaid caregivers are primarily family members but also include friends. In 2009, they provided 12.5 billion hours of unpaid care, a contribution to the nation valued at almost $144 billion.

Source: Alzheimer’s Association, “2010 Alzheimer’s Disease Facts and Figures”, Alzheimer’s & Dementia, Volume 6