Alzheimer's disease (AD) is the most common type of dementia, a group of brain disorders that cause impairment in mental abilities, such as memory and reasoning. When AD affects individuals in their 30s, 40s, and 50s it is called early-onset AD. Late-onset AD is the most common form and usually occurs after age 65.
In the initial stage of AD, people may begin to experience memory loss and confusion, which may be mistaken for signs associated with the normal aging process. However, symptoms get worse over time resulting in personality and behavior changes, difficulty in decision making, problem-solving and recognizing family members or friends. In AD the brain cells degenerate and die, eventually causing severe loss of mental function.
During the disease process of AD amyloid plaques and neurofibrillary tangles build up in the brain. Amyloid plaques are deposits of a protein called beta-amyloid on the nerve cells and tangles are deposits of a protein called tau inside the nerve cells. The plaques and tangles start to destroy more brain cells, leading to cell death. Eventually, the loss of connection between the neurons leads to significant brain shrinkage.
There is currently no treatment to cure or stop the progression of AD, but there are various medications available to keep the symptoms getting worse for a limited time. Medications prescribed for AD can help individuals to carry out the simple tasks of daily living and also help with certain behavioral and personality changes.