How Alzheimer's Can Cause Changes in Personality

When most people think of Alzheimer's disease, the symptoms that typically come to mind are those relating to cognitive functioning: memory loss, word-finding difficulties, poor judgment in decisions, and disorientation regarding the day, time or place. While these are hallmarks of Alzheimer's and other dementias, there's another symptom that can be challenging for family and friends to cope with: personality changes.

Older woman with her hand to her forehead being comforted by another woman
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Personality changes don't always develop, but they are a frequent result of Alzheimer's disease and other types of dementia, and one that can be hard to accept for loved ones. Some examples of personality changes include:

  • Freda has been the most caring, friendly and positive woman around. She always wants to know how others are doing and how she can help. Since she developed Alzheimer's, she no longer asks people how they're doing and seems to just ignore them all. Instead, if anyone asks how she's doing, she constantly complains.
  • Sam, who has always adored his wife and been faithful to her, now makes sexual advances to the nurse aides who care for him.
  • Fred, a retired psychologist who had a very successful practice, now makes rude and cruel comments to those around him. One of his strengths before Alzheimer's had been his kindness and ability to relate to others.
  • Sally is a deeply religious woman who has always been careful with her words. She now frequently fills her conversation with offensive, foul language.
  • Martha, the matriarch of the family, has been the informal social director of the extended family, frequently organizing reunions. Now that she has Alzheimer's, she shows no interest in getting the relatives together. When someone else coordinates it, she is apathetic and no longer seems to care about connecting with the family.


There are several possible causes of personality changes. The most prevalent cause is related to the changes that happen in the brain which affect a person's characteristics and personality. The brain is actually physically changed by Alzheimer's disease, with parts of it atrophying and other areas becoming malformed, twisted or clumped together.

Other causes can include confusion, too much noise or activity, lack of sleep, anxiety, fear, depression, pain, the effects of medications, and delusions.

How to Cope

  • Remind yourself that the changes are due to the disease. She is not purposely trying to hurt your feelings or annoy you.
  • Don't argue with him. It won't help.
  • Focus on her feelings, not her words,
  • Set reasonable expectations.
  • Use redirection and distraction instead of attempting to reason with the person.
  • Address any physical, environmental or psychological causes of challenging behaviors.
  • If the personality change is sudden, you may need to contact the physician to consider if the sudden changes could be caused by delirium.

A Word From Verywell

Sometimes, personality changes in dementia can be frustrating or feel hurtful for loved ones. In these situations, it can be helpful to understand why these changes develop and how to respond to them. Taking a deep breath and remembering that those changes are often a part of the disease can help you continue to treat your loved one with compassion, kindness, and dignity.

1 Source
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. National Institute on Aging. Managing personality and behavior changes in alzheimer's. Reviewed May 17, 2017.

Additional Reading
  • National Institutes of Health. National Institute on Aging. Alzheimer’s Disease Education and Referral (ADEAR) Center. Alzheimer's Caregiving Tips: Managing Personality and Behavior Changes.

  • Alzheimer Scotland. Behaviour that challenges - understanding and coping. 

By Esther Heerema, MSW
Esther Heerema, MSW, shares practical tips gained from working with hundreds of people whose lives are touched by Alzheimer's disease and other kinds of dementia.