My mother has dementia and she is constantly obsessing about my brother not giving her insulin each morning. He gives it to her everyday. Any suggestions?

I would suggest that you make a chart and put a check mark on the box when she gets the injection, so she can look back during the day and see that it was done, but, honestly, it won't likely work. I tried all kinds of things like that with my LO when she started with memory loss. However, charts, signs, reminders, etc. didn't see to make any difference, since it's the the process of thinking that was impaired and no amount of trying to explain things, show charts, lists, etc. made any difference. The only thing that I could do was to keep telling her the same thing over and over. Of course, she would forget in a few minutes, so you have no choice but, to explain it over and over. It can be very exhausting and overwhelming, but, I'm not aware of any other option, EXCEPT as stated above. Talk to the doctor about medication. I found that my LO was quite anxious and she would obsess over certain things. Medication for anxiety did help her not obsess and stress so much.

I will say that eventually that stage did pass.

Talk to her doctor about getting meds for agitation.

I was about to suggest making a check off list, and then your brother could tell her, well, "I'm pretty sure we did that this morning, let's go check the list and tell me if we checked it off?" That used to work with my mom for certain daily things.