| Prevalence |
Approximately 5 million older Americans are estimated to have dementia (Alzheimer’s Association, 2007). In 2010, more than 35 million people worldwide were estimated to have dementia (Prince et al., 2013). Approximately 1–2% of 65-year-olds are diagnosed with dementia, but as many as 30% of 85-year-olds are so diagnosed. |
| Comorbidity |
Depression (Kales et al., 2005; Snow et al., 2005) and psychotic symptoms such as hallucinations and delusions (Tractenberg et al., 2003) commonly co-occur with dementia. |
| Onset |
Onset usually occurs late in life. Cognitive deterioration can be rapid or gradual, depending on the cause of the dementia. Impaired learning and recall are early signs of some types of dementia. |
| Course |
People with dementia may be unable to perform complex tasks in new situations but may still be able to perform simple ones in familiar surroundings. Some types of dementia, such as that caused by Alzheimer’s disease, get progressively worse; other types of dementia, such as that caused by HIV infection, can get better with treatment of the underlying cause. Still other types remain relatively unchanging. |
| Gender Differences |
Dementia is slightly more common in males than in females. |
| Cultural Differences |
Some cultures and ethnic groups—such as African Americans, Asian Americans, and Hispanic Americans—may be more tolerant of impaired memory and other cognitive dysfunctions that affect elderly people, in some cases viewing these changes as a normal part of aging. These family members thus may wait longer before seeking medical assistance for an older person with dementia (Cox, 2007). |
| Source: Unless otherwise noted, the source for information is American Psychiatric Association, 2000, 2013. |