Is Alzheimer’s the Most Common Type of Dementia?

James M. Ellison, MD, MPH

Swank Center for Memory Care and Geriatric Consultation, ChristianaCare

  • Expert Advice
Published on:
Blocks with letters on them spelling the word dementia.

This article discusses the most common type of dementia, resulting in 60 - 80 percent of all cases of dementia diagnoses.

​Andrew* first noticed his mother’s forgetfulness at her 75th birthday party. She did her best to hide her difficulty, but it was obvious to him that she was having trouble remembering the names of several more distant cousins who had come to celebrate with her. Had her husband still been alive, he would have covered for her by greeting everyone by their names in order to remind her. Thinking back, Andrew realized that his mother had been having noticeable trouble during most of the previous year. Her reaction after her husband’s death was more than simple grief. She was forgetting details of things that had happened. She seemed to be having more trouble using her microwave and food processor. She had misplaced some important bills and then thrown them into the garbage by mistake. She sometimes called Andrew to ask questions about things he’d already discussed with her.

By the time she approached her 76th birthday, Andrew was in the habit of stopping by her house on a weekly basis, helping with chores, and making sure the garbage was put out and the refrigerator was kept clean. It was pretty clear that he needed to help his mother get additional support in her home if she was to continue to live there. He also considered involving her primary care physician or a memory disorders clinic. But he wondered whether there was any point. After all, wasn’t his mother just going to go through a bunch of tests and then be told she has Alzheimer’s disease, and there isn’t anything that will help?

*The names and details in this story are composite and fictitious. They do not identify specific individuals.


The answer to the question “Is Alzheimer’s disease the most common type of dementia?” is “yes.” Alzheimer’s disease is indeed the most common cause of serious cognitive problems among older adults. It is one of the major causes of death, and it is one of the costliest of diseases for our health care system. As yet, we have no cure.

But there is so much more to say about this matter!

One of my professors in medical school used to remind us that there are many patients who cannot be cured, but few who cannot be helped. Help for a person with Alzheimer’s disease includes attention to their safety and comfort, medical care of conditions that might further interfere with their best level of functioning, and support of their caregiving system.

Recent advances in neuroimaging have made it possible for us to recognize Alzheimer’s disease even before severe cognitive symptoms have developed, and at the earliest stage of Alzheimer’s disease there may be opportunities to help delay or prevent worsening. Medical disease management, physical activity, good nutrition, cognitive stimulation, social engagement, stress reduction, and healthy sleep habits can all promote brain health.

At the earliest stage of cognitive symptoms, participation in clinical trials may offer some affected individuals an opportunity to delay the effects of the disease—and many possible therapies are currently in testing.

It is also important to keep in mind that although Alzheimer’s is the most common type of dementia, it is definitely not the only one. A recent study called IDEAS (“Imaging Dementia, Evidence for Amyloid Scanning”) reported that nearly a third of patients referred for amyloid scanning with a likely diagnosis of Alzheimer’s disease actually had a different condition altogether. Vascular dementiaLewy body dementiafrontotemporal dementiaParkinson’s disease dementia, alcohol-related dementia, dementia related to HIV infection, and dementia associated with head trauma are other important causes of major neurocognitive disorder. They are not all curable, but various treatment approaches can reduce symptoms, reduce caregiver burden, and improve quality of life. In addition, there are reversible causes of cognitive symptoms that may look just like dementia yet improve considerably when treated correctly. Adverse effects of inappropriate medications or of toxic substances, depression, sleep disorders, and some infections are among the many treatable causes of cognitive symptoms.

For Andrew and anyone in his situation, I would suggest seeking the help of a physician trained to evaluate and treat dementia. Sometimes this can result in discovery of a curable condition. Almost always, it can result in getting specific and useful advice and assistance.

About the author

Headshot of Dr. James Ellison

James M. Ellison, MD, MPH

Swank Center for Memory Care and Geriatric Consultation, ChristianaCare

James Ellison, MD received his medical degree from UCSF in 1978 and trained in psychiatry at the Massachusetts General Hospital (1979-1982).

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