What are good topics to distract those in a fixated mindset?

You are so right, Madeaa. Providing distractions is an effort. Caring for someone with dementia is an extremely challenging, tiring, and effortful situation.

I agree with what has been said. For me now, the distractions are becoming a problem for me. I am anxious about them, not good. I am pursuing other avenues for now, but when I did use them I found talking about my dad with her worked well. She would go off in a repetitive dialogue about the past, I tried to listen but found myself getting anxious over the repetition. I would think talking about anything that is/was important to your loved one works for as long as you can deal with it. Showing pictures, getting a good movie on, nice snack tea and biscuits, they do work but it is an effort.

Yup. For most of us, food is a great distractor. :)

(This can be unfortunate if we reach for a Snickers every time we want to be distracted from our troubles, but it sure beats being stuck on obsessions with a person who has dementia.)

Rootbeer float??? Milky way???? Cookies?????? It worked on me! I'm distracted! :)

Favorite foods often work. "Well, let's come back to this topic later. Maybe we'll have some new thoughts about it then. But right now, would you like me to make you a rootbeer float?" (Should I get a Milky Way out of the vending machine? ... How about a dish of peaches? ... "I'm going to have a couple of cookies. Do you want a couple, too?"

Accusations: He says: I'm NOT accusing you, BUT no one has been in my apt but YOU and half the package of pencils I bought (6 months ago) are missing. (LOL)
I say: Uncle dear, if I wanted to steal something (even tho his not accusing me), I would pick something much more valuable than your pencils. Have you noticed anything else missing lately? (He says NO). Well, I don't even remember seeing a package of pencils in that drawer (let alone buying them). Why don't we take the rest of them and put them in a different place? (Then I help him decide on a new place to put them).

Complaining: The Pity Party
He says: If I only had my eyes, I wouldn't have to rely on anybody to to anything for me. I could drive, I could walk, I could shop. etc.
I say: What if you could see, but you couldn't walk and needed a wheel chair? What if you had a stroke and couldn't speak to tell anybody what you were feeling or what you needed? What if you were so bad off you had to be in a NH?
He says: Yeah, I guess I'm not so bad off compared to some others. And I'll NEVER go to a NH!!
I say: Well then count your blessings that you have someone who cares about you enough that will respect your wishes as long as possible, that you have food on the table and money to pay your bills. No more complaining!