People write in this forum about their elders getting angry, depressed, blaming and paranoid. And it's clear that psychotropic drugs can help, whether these moods are in reaction to loss of function and independence or symptoms of dementia. But my mother is blaming and paranoid without any of those additional reasons! and has been all her life. It's a personality disorder, and one of the hallmarks of the disorder is that she can't tolerate the notion that there's any step for HER to take to make her life better. It's all everyone ELSE's doing, problem, etc. The crazier she feels, the harder she works to get other people, especially her husband, "diagnosed" as the disordered person. It follows that she will never take medication -- doing so would suggest that there was something off with her. She also won't accept the approach "ok, so the problem is dad, how awful for you, this will help you cope with it" because of the paranoia -- she thinks she'll react terribly to a drug, and/or that we're trying to dull her wits so we can take advantage of her. (She also won't give a health care proxy to anyone...) Everyone just copes, and I'm figuring that if she gets bad enough for a crisis that may shift things. But perhaps other people have ideas we haven't tried?
Unfortunately, you cannot force her to take a Rx drug. Also, you will NEVER change her repetitive behaviors.
The best you can do is "deflect" her negative or inappropriate comments during conversation. ie: "Oh that is interesting, Mom. By the way did you hear that we are going to have great weather this week? Would you like to go out for lunch?" You are replacing the cycle of negativity with positive statements that require her to respond in kind. If she comes back to the same old drone...then, just have an "exit" plan ready. Leave the room or end the phone call. There is no reason for you to be constantly subjected to the "show."