Campbell has a history of addiction to alcohol for many years and now he is diagnosed with Alzheimer's disease.

Although no strong connection has been established by doctors between alcohol consumption and the disease medical experts, however, feel that heavy alcohol consumption has both immediate and long-term detrimental effects on the brain and neuro-psychological functioning.

Alzheimer's disease, which is a progressive degeneration of the brain, claims about 23,000 American lives a year. It is the eighth leading cause of death among the elderly in the U.S.

The early onset of Alzheimer's can develop in people at an age as young as 40, but most victims develop and progress to the next stage by the time they turn 65. Alzheimer's is a form of dementia and is particularly dangerous because it robs people of their mental faculties and memories.

Some common early symptoms of Alzheimer's disease include confusion, disturbances in short-term memory, problems with attention and spatial orientation, changes in personality, language difficulties and unexplained mood swings.

After Glen's detection of the disease, lets have a look at some of the celebrities who succumbed to Alzheimer's Disease: