Step 1: Understanding dementia.
Dementia is a general term for a decline in cognitive ability severe enough to interfere with daily life. Alzheimer's disease is the most common cause of dementia.
Step 2: Analyzing the options.
(1) Alzheimer's disease: Alzheimer's disease is the most common form of dementia, accounting for 60-80% of cases. It is characterized by memory loss, confusion, and changes in behavior.
(2) Vascular dementia: This form of dementia is caused by impaired blood flow to the brain, often due to strokes, but it is less common than Alzheimer's.
(3) Lewy body dementia: Lewy body dementia involves abnormal protein deposits in the brain and is less common than Alzheimer's.
(4) Frontotemporal dementia: This type of dementia affects the frontal and temporal lobes of the brain, but it is less common than Alzheimer's disease.
Step 3: Conclusion.
The most common form of dementia is (1) Alzheimer's disease.