Why is that?
Although people of all ages can suffer from dementia, the diseases and disorders that most commonly cause dementia, including Alzheimer’s, affect primarily older individuals. There are, of course, exceptions. Certain diseases, such as AIDS and Wilson’s disease, are more common in younger individuals, while hydrocephalus and brain tumors can affect people of any age. We take a detailed look at the underlying causes of dementia, who’s affected and at what age in Chapters 2 and 3. For now, it’s important to know that, while dementia can affect people of any age, the vast majority of people with dementia are senior citizens. In fact, dementia is the major cause of long-term disability in old age.