Accuses others of own mistakes
When it happens
From later in mild-stage dementia through moderate-stage dementia
Why it happens
At first, the accuser may be trying to cover up embarrassment over mistakes by blaming someone else. As the disease progresses, the person loses awareness of having dementia. Therefore when something happens that he can't explain, and given that he's lost the ability to reason, his mind works to create an explanation, which is that someone else must have done something/taken something/lost something.
What you can do
Don't bother trying to correct the person or trying to convince him or her of the truth.
Try to stay calm if you're the person being accused. Remind yourself it's the dementia talking, not the person.
Reassure relatives, hired help, or others who are accused that you know they're not guilty.
Be sure there's a plan in place to manage finances and that records are in good order. The reason isn't to convince the person with dementia that everything's OK, but to safeguard against other relatives starting to believe the accuser.
You may want to keep an inventory of personal effects (jewelry, mementoes), for the same reason.
If you can, keep multiples of things that get mislaid often, such as glasses, hats, or canes.