Dealt with this with my Mom and FIL
Both cases were tough to deal with
Both were very defiant at times and wouldnt take meds
Took several caregivers to help with my FIL including my wife and I but my Mom went downhill so fast we had to put her in a nursing home because it was just too much
My Grandfathers Mother had it, and I am pretty sure two of his brothers did as well. We are doing everything we can do to keep him out of the nursing home, but at this point it isn't up to us. It is my grandmothers decision, she is the one dealing with it day in and day out.