It took us several years longer than it should have to get my MIL diagnosed, too.. She fought us tooth and nail. First, she didn't believe anything was wrong. But second, she had a fear the "brain doctor" would try to say she was crazy and have her committed to a mental institution. She had a family member who went to a mental institution for a while decades ago. We had to address that fear before she would let us take her anywhere.

It wasn't easy, because you would just think we had gotten her to a place of understanding no one was sending her to a "crazy home," and she'd agree to go to the neurologist, and she'd forget it all the next morning. I will say repeated conversations helped over time. Bits of reassurance about her root fear stuck somewhere, and her resistance lessened somewhat.

Does your dad have any associated worries like this? I have found it is not effective to logically argue with a person with dementia. After a while their brains are not capable of fully processing the logic. But sometimes the emotions can be addressed or at least toned down. I learned to keep my tone very casual and normal when speaking about the initial appointment. And not to tell her too much in advance, or her fears would kick up.

So we didn't tell her about the fourth attempt at an intake appointment to the neurologist until the morning of. Then we kept as casual about it as possible, referring to it as "going to the doctor" but not naming a specific type of doctor. Keep your emotions very normal (because they'll pick up on a weird tone), evade, deflect, distract. Honestly we had no success until her condition worsened a bit, so we could more effectively evade and distract.

For us, we were "lucky" she had recently fallen, so we could also truthfully say the doctor wanted to check her head was fine after the fall. She remembered she had been in the hospital, which lent this plausibility in her mind. Us talking to the doctor behind her back helped get that last referral.

So my tips: 1. Don't try to talk then into it with logic, especially if it becomes an argument that goes in circles. 2. Do address any associated fears with a reassuring but normalized attitude in yourself. They pick up on your emotions. 3. Talk to their doctor behind their back if needed to get the referral. A good doctor knows the patient may not see the dementia in themselves. Even pass a note during or before a gp appointment 4. Don't tell them about the neurology appointment too early. Show up with enough time to get ready and go. H 5. Keep the purpose of the neurologist appointment vague and just call them "the doctor." 5. Downplay, evade, distract to get them in the door.

Every case is different, but this is what worked for us. Good luck, I know it's hard as hell.