Is paranoia part of dementia?

Yes, definitely.

Not all paranoia is associated with dementia. And not every case of dementia includes paranoia. But paranoia is extremely common in dementia.

Oh my, yes! I am pretty positive it is a big part of dementia and so hard! My grandma would accuse her son of stealing from her in one breath and then say how wonderful he was and he would give the shirt off his back to anyone in the next. It just is a disease that makes no sense. My grandma would also say people were in her house but it was her tv. My Mom has vascular dementia and doesn't exhibit such paranoia -she is suspicious of my Dad and the money but I think that is more because he controls it now. She doesn't have good reasoning skills but she has some - so my Dad is kinda in a hard spot. IDK. It is hard to figure out. But I do think that with Alzheimer's paranoia is very common.