Alzheimer’s and dementia are diseases of the brain that are very different from memory problems of normal aging. They are also different from each other.
Dementia is the umbrella term used to describe several diseases that cause changes in the brain that lead to memory loss and language and reasoning difficulties, ultimately disrupting everyday functioning.
Meanwhile, Alzheimer’s disease is one kind of dementia—and the most common. Studies show older people with Alzheimer’s often have one or two other kinds of dementia as well, a condition known as “mixed dementia.”
Alzheimer’s is a disease in which a toxic protein called beta-amyloid slowly accumulates and eventually disrupts another protein called tau that is critical to brain function, explains Richard Caselli, M.D., associate director and clinical core director of the Alzheimer’s Disease Center at Mayo Clinic in Arizona.
“This damaged tau not only leads to dysfunction and ultimately the death of the affected neuron, but also spreads to other brain cells, leading to their dysfunction and death,” he says. The areas of the brain that are affected determine a patient’s symptoms.