Dementia is an umbrella term to a range of conditions that cause damage to the brain. This damage includes the loss of cognitive functioning—thinking, remembering, and reasoning—and behavioral faculties to the extent that it disrupts a person’s ability to carry out everyday tasks. There are many types of dementia with Alzheimer’s disease being the most common type. Other types include Huntington’s disease, Parkinson’s disease, vascular dementia, dementia with Lewy bodies and frontotemporal dementia.
The causes of dementia vary and are identified by the types of changes that are occurring in the brain. A variety of screening tools including blood tests, mental status assessments, and brain scans are used by doctors to diagnose the type of dementia. It is not uncommon for an individual to be diagnosed with more than one form of dementia.
Alzheimer’s disease is the most common and well-known type of dementia. It is recognized by the abnormal build-up of proteins in the brain that forms plaques and tangles that destroys brain cells, leading to loss of memory and other cognitive skills, personality changes, and difficulties performing daily activities. It usually develops slowly and gradually gets worse as brain function declines and brain cells eventually stop functioning.
Short term memory loss is often one of the first symptoms of the disease, but it is important to remember that symptoms and experiences of the disease vary from person to person. A majority of individuals who are diagnosed with Alzheimer’s have the late-onset form of the disease and do not exhibit symptoms until their mid-60s. Approximately 5% of all individuals with Alzheimer’s have the early-onset form of the disease and develop symptoms between the ages of 30 and 60. Most individuals with Down Syndrome develop Alzheimer’s with increased chance of developing the early-onset form of the disease versus the late-onset form.