Is extreme selfishness and narcissism an inevitable result of advancing dementia?

My mom's MC had some of the sweetest, most adorable residents who just got sweeter and more adorable.

As others have said -- and interestingly, something my dad told me at least 20 years ago long before Mom developed dementia -- a personality gets magnified as we age. My dad never had dementia, but if possible, he was kinder and more loving as he aged, while my mother became more "crunchy" as she aged. She was also kind and loving, but she had her opinions and they became more unfiltered as the years passed. Overall she was still pretty nice and never lashed out at family, but her temper tantrums were more related to her existence declining into being one giant medical issue.

First you should understand that people who are not facing difficulty dealing with this kind of attitude are not coming to sites like this and telling their stories, so there is a confirmation bias at play.
It's my opinion that while many people have told stories of those with dementia becoming someone markedly different from the person they used to be, to expect a person who has been a lifelong self centred gossip to become a kind and compassionate saint seems like wishful thinking. I think many (most?) of us become more selfish and less altruistic when faced with a life crisis because we're focused on the desire to survive with our life unchanged and intact. We may lash out in fear and confusion, we may rage at the hand life has dealt, and as dementia progresses we may genuinely forget life lessons and revert to childhood attitudes and prejudices because in our mind we ARE that child. As we lose our physical as well as the mental capacity to care for even our basic needs we essentially become as needy as a small child, and it takes a special kind of understanding and patience to cater to the whims and needs of someone who is not a child that will grow toward independence but the opposite of that.

PS - In many ways my mom became incredibly needy and self centred, she also never failed to be thankful for any little bits of kindness and comfort offered.

No. I got to know many Alzheimer's and dementia people over the years while my mom was in care. Even in the nursing home, where the feeling of the place was dismal (to me anyway), some of the ladies were downright cheerful. Most were slumped sleeping in their wheelchairs, but when awake I saw quite a bit of pleasantness about them. One lady was always happy, especially when there was music on. Some were angry and complaining, yes. My mom actually got sweeter and nicer as the disease progressed. Everyone mentioned that she was a joy to be around.

Unfortunately, I think that a psychopathic narcissist will lose the ability to manipulate and gaslight people as effectively as they could before dementia. Like my mother, who was always able to be the sweetest lady in front of her " audiences" , but with dementia , has become the spawn of Satan ...amd no longer saves her venom and bullying for just her family members , now lashing out at whoever tries to set boundaries or reason with her. I guess it really depends on how entrenched the personality disorder has been during the persons life. Sending prayers for you.

In my experience with my mother who had dementia, the personality they used to have is MAGNIFIED once they get dementia. My mother was similar to your MIL; gossipy, self centered *to the max*, vain, etc. So as her dementia advanced, those traits magnified to the degree that she became horribly mean, critical, accusatory towards me & others, suspicious and otherwise insufferable to the Nth degree. All of her worst traits became so horrid, she was impossible to deal with, for the most part. She lived in Memory Care AL so I did not have to deal with her 24/7, thankfully. But as her dementia became VERY advanced, she became somewhat nicer........she forgot who she hated and how much she hated them, so she was a bit softer around the face and not quite so hateful and bitter, thank God.

Dementia is really an ugly thing for most people. There are some elders, however, who do not become ugly, mean and hateful with their disease. But it seems to me that those were the people who were ALWAYS kind and sweet in the first place. Most neurologists will agree with that statement. I'm sure there are exceptions to the rule, however.

Hopefully you will hear from those exceptions who will comment with upbeat stories of their loved one with dementia who were very sweet and kind as time wore on.

Best of luck.

I think lealonnie's answer is spot on. We become more like ourselves as we age.

I'm a little crazier and more emotional (but I keep that under wraps as it drives DH nuts to see me have 'emotions'.

It's made DH crankier and less pleasant to be around. He's truly retiring this year and so far, retirement looks like sleeping until 1-2 pm. I'm halfway through my day by then! His only current hobby is wandering around Home Depot.

HIS mother is a complete harridan. No attempts made at even trying to be 'nice', much less enjoyable company. Nobody is surprised by this, but it's really, really hard for those who have to take care of her.

Both my grandmothers were sweeter and nicer as they grew old. It was a gift to be around them and for my kids to all remember them.

No it isn't. My ex mil was a "nice person" and stayed much the same during her 20 year bout with Alzheimer's. A person may stay the same or get worse or get better. We have read on here of people who mellowed with Alz though my sense is that it is not common. We certainly see many posts here about people with Alz being very difficult, but their caregivers are the ones who need the most support so there is likely a higher proportion of caregivers of difficult Alz patients here compared to the total.

I would say no, it definitely is not inevitable. You'll read many stories on this site about people who become mean and intolerable with dementia. I have no doubt that many do. My FIL was one of those that didn't. He was always an easy-going, friendly person (to me at least!). As he slid downhill into dementia, he became almost child-like and more affectionate. He'd say silly things and acted more like my MIL's child than her husband.

That doesn't mean their behavior can't be problematic, though. He was a wanderer, there were several times when the police and/or my husband had to be called to look for him when he left the house and got lost. He often wanted, and tried, to "go home", though he was living in his home of almost 60 years. At the end he didn't know any of us, including his wife.

It's not always that the person turns into a monster, but it's always sad.

ThinkingOutLoud: My late sister in law always berated her spouse. After she was diagnosed with Alzheimer's, she was uncharacteristically kind to him. This may be a little off topic, but I wanted to share it nonetheless.

My Mom is sweet and polite even when she doesn't know who I am. When she does know who I am, she's feisty.
But, she is also selfish. Her window of knowing anything or anyone around her is getting smaller and smaller, so what other focus would she have but her immediate needs and wants?

Plus, how terrifying it must be to have flashes of abilities and then flashes of confusion. When aware, you know you are losing abilities and memories, when unaware, everything is a muddle.