From the LewyBody Organization...

Most people with dementia undergo behavioral changes during the course of the disease. They may become anxious or repeat the same question or activity over and over. The unpredictability of these changes can be stressful for caregivers. As the disease progresses, your loved one's behavior may seem inappropriate, childlike or impulsive. Anticipating behavioral changes and understanding the causes can help you deal with them more effectively.

What is the behavior telling you?
Persons with dementia often lose their ability to express themselves before they lose their ability to understand. Behavior becomes a means of communication. Ask yourself why your loved one is behaving this way. Then you can take steps to manage the behavior.

Tips for managing behavioral changes
When your loved one exhibits an undesirable behavior, your reaction may be to try to stop or change the behavior. But remember, you can't reason with or teach new skills to a person with dementia. Instead, try to decrease the intensity or frequency of the behavior. Consider these approaches:

Remember that your loved one isn't acting this way on purpose. Try not to get angry or upset or take it personally.
Speak calmly and softly to the person.
If the behavior is aggressive, back away. Give your loved one space. Then calmly approach him or her. Don't argue.
Consider the potential cause of the behavior. Is your loved one tired, hungry, in pain, frustrated, lonely, bored? Could it be a side effect of medication?
Respond to the emotion, not the behavior. If your loved one keeps asking about a certain family member, he or she may need reassurance that this person is healthy and safe. Avoid trying to reason with the patient, this may often lead to frustration for both of you, because he or she may be unable to follow lengthy explanations.

If a behavior continues, keep a journal to identify patterns (time of day and possible triggering events), and this may provide clues regarding ways to intervene.

Validate, Join and Distract
One effective method for managing a difficult or annoying behavior is to validate, join and distract. For example, if your loved one constantly heads to the door asking to go home, efforts to try to distract him may not work. By simply interrupting the behavior, you don't gain an understanding of why the behavior is occurring.

A more effective approach is to try to validate the emotion that you think is underlying the behavior. For example, say something like, "I know you miss your family." Then sit down and look through family photo albums. This way, you haven't just distracted the person but you've first joined in and validated the person's emotions. Validating, joining and then using distraction may be most effective with people who are in the early to middle stages of the disease.

You know your loved one best
Let your knowledge of your loved one who has dementia guide your choices for distractions. For example, if she was a homemaker, stirring cookie dough or folding laundry may be meaningful activities. Responding to challenging behaviors takes creative solutions, patience and a willingness to be flexible.