Alzheimer’s Disease: 2015
The comprehensive 2015 report from the Alzheimer’s Association states that “Alzheimer’s disease (AD) is a degenerative brain disease and the most common cause of dementia…AD is characterized by a decline in memory, language, problem-solving, and other cognitive skills that affects a person’s ability to perform everyday activities. This decline occurs because nerve cells (neurons) in parts of the brain involved in cognitive function have been damaged and no longer function normally. In AD, neuronal damage eventually affects parts of the brain that enable a person to carry out basic bodily functions such as walking and swallowing. People in the final stages of the disease are bed-bound and require around-the-clock care. Alzheimer’s disease is ultimately fatal….”
AD is characterized as the most “common cause of dementia and accounts for an estimated 60-80 percent of cases….” The report states that “difficulty remembering recent conversations, names, or events is often an early clinical symptom; apathy and depression are also often early symptoms. Later symptoms include impaired communication, disorientation, confusion, poor judgment, behavior changes and, ultimately, difficulty speaking, swallowing, and walking….”
With regard to age, the association states that, “the greatest risk factor for Alzheimer’s disease is age. Most people with Alzheimer’s disease are diagnosed at age 65 or older. People younger than 65 can also develop the disease, although this is much more rare (see the Prevalence section). While age is the greatest risk factor, Alzheimer’s is not a normal part of aging and age alone is not sufficient to cause the disease….”
With regard to mild cognitive impairment (MCI), the report states that MCI is a condition in which an individual has mild but measurable changes in thinking abilities that are noticeable to the person affected and to family members and friends, but do not affect the individual’s ability to carry out everyday activities. People with MCI, especially MCI involving memory problems, are more likely to develop Alzheimer’s and other dementias than people without MCI. Revised criteria and guidelines for diagnosis of Alzheimer’s disease published in 2011 suggest that in some cases MCI is actually an early stage of Alzheimer’s or another dementia. However, MCI does not always lead to dementia. In some individuals, MCI reverts to normal cognition or remains stable….”
Regarding prevalence of Alzheimer’s disease (and other dementias) in the United States, they state that “an estimated 5.3 million Americans of all ages have Alzheimer’s disease in 2015. This number includes an estimated 5.1 million people age 65 and older and approximately 200,000 individuals under age 65 who have younger-onset Alzheimer’s. One in nine people age 65 and older (11 percent) has Alzheimer’s disease. About one-third of people age 85 and older (32 percent) have Alzheimer’s disease. Eighty-one percent of people who have Alzheimer’s disease are age 75 or older.
For More Information, References, and Recommendations
Alzheimer’s Association. 2015 Alzheimer’s Disease Facts and Figures. Alzheimer’s & Dementia 2015;11(3)332+.