Dementia can cause changes in a person’s personality and behavior. For example, they may become angry, violent, or agitated. They may also experience apathy, or a lack of enthusiasm or interest.

Alzheimer’s disease and other types of dementia can affect a person’s personality and how they behave.

Symptoms like mood changes may happen with early dementia. Other personality and behavioral changes may develop as the condition advances.

Read on to learn more about how dementia can affect personality and behavior. This article also looks at what to do if a loved one experiences personality changes due to dementia.

Dementia can cause a range of personality and behavioral changes. Some, like mood changes, may happen with early dementia. Others may happen with the later stages of dementia.

Changes can be gradual for some people, while for others, they can begin suddenly.

It’s important to note that dementia can affect each person differently. But some common changes in personality and behavior include:

  • worry or agitation, such as following you around or asking a lot of questions
  • apathy, or indifference, which can show as a lack of interest or enthusiasm
  • anger
  • violence or threatening violence
  • delirium, which can cause:
    • changes in alertness or energy
    • difficulties focusing
    • fidgeting or moving more slowly
    • problems with communication
  • accusing you of doing things or believing that you’re an imposter, which can happen due to hallucinations and delusions
  • depression
  • impulsive behavior
  • compulsive behavior
  • wandering

This isn’t an exhaustive list of personality and behavioral changes that a person may experience with dementia. If a loved one or somebody you care for has dementia, it can be helpful to write down any changes you notice and discuss them with their doctor.

Dementia may cause personality and behavioral changes due to a loss of neurons in parts of the brain, according to the UCSF Memory and Aging Center. Neurons are nerve cells that send messages throughout the body.

The changes that a person with dementia experiences can depend on which parts of the brain lose neurons. For example:

  • Changes in focus and motivation may happen if there’s a loss of neurons in the frontal lobe, which is behind the eyes. This can affect decision making and planning.
  • Damage to the hippocampus can affect short-term memory, but the person may be able to recall events from long ago, particularly in the early stages.
  • Damage to the brain’s left hemisphere can affect memory and language. For example, the person may not be able to find the right word to use.
  • The temporal lobes affect vision. If damage occurs here, it can affect the person’s ability to recognize faces or objects.
  • If damage occurs in the right parietal lobe, difficulties with spatial awareness and navigation can occur. For example, the person may find it difficult to climb stairs.

If a loved one has dementia, or if you’re a caregiver for somebody with dementia, there are various things you can do to help them.

Ways to help include:

  • trying to stay patient and calm
  • trying to understand what the person’s trying to communicate and adapting to their way of communicating if necessary
  • creating an environment and a routine that’s familiar and offers structure
  • talking with other caregivers or friends who may be in a similar situation
  • talking with the person’s doctor to find out if the changes are due to dementia or another cause, like a medication side effect

A medical professional can give you more advice on how to help somebody with dementia who may be experiencing personality or behavioral changes.

Dementia can cause a range of personality and behavioral changes, like apathy, depression, delirium, impulsive behavior, and agitation.

These changes usually happen due to damage in different parts of the brain. The personality and behavioral changes that dementia causes will be different for each person.

You can help a person experiencing these changes by staying calm and patient, adapting their environment and routine, and understanding their way of communicating. Speaking with their doctor and other caregivers may also help.