I have an 88 year old grandmother. She had 3 kids - now in their 50's and early 60's, themselves. When they were young, she was a very unstable and unfit mother. Made very poor decisions, was financially unstable, wouldn't hold a job for long and moved her kids around constantly from apartment to apartment trying to skip out on the rent because she "couldn't work and watch the kids" as an excuse. The kids had a horrible childhood, frequently changed schools, etc. She seems to have lacked common sense for all of her life and made the "wrong" choice at every turn in life. She'd go to a car lot in her young years decades ago, get a car and when it needed maintenance, she'd 'return' it and get another car. Just the same revolving pattern. Never owned her own house. Never saved for retirement. Ended up on SSI/Disability in her 60's and complains a lot. She didn't have enough work credits by retirement age. As a result of Disability (Phlebitis), she does get Medicaid and Medicare and therefore has no idea what accountability for bills and such are. She is highly unthankful for paid doctor visits and sits around berating doctors because she doesn't think they're fixing her medical issues. She has an odd perception of how a doctor checks patients. Her daughter took her to get her sore throat checked and literally watched the doctor touch my grandmother's throat to check it. She claims he touch her 'arm' and never checked her throat.
Decades ago, some type of psychologist or psychiatrist diagnosed my grandmother as paranoid schizophrenic with high anxiety. She wouldn't take the medication, of course. So she has delusions of a former male neighbor from decades ago who has speakers/mics set up all over the neighborhood. She hears him playing all sorts of 'tapes' of people dying, loud music, he says sexual stuff, mean things about her and family, etc. She once called the bomb squad to the house next door, claiming someone in the attic said a bomb would go off in 15 minutes. Police refused to take her for a mental evaluation. She described an "awful crackling" upon opening the back door and insisted that "something was about to blow up" and it was literally raining hard outside and hitting the neighbor's gutters next door. We thought she had a stroke or something at first.
She did a lot of odd jobs earlier in life that were unproductive...e.g. in her 60's, she wanted to take a push mower around in her car trunk mowing random lawns for $10 or $15 for probably 10-15 years for cash. Before that, she played around as a taxi driver for years, barely making any money from it. Just basically wasted her life and was unproductive. She has lived with her daughter for the last 30+ years and the daughter (my mother) and grandson (myself) have been taking care of her.
Her mannerisms are of course very odd. She is a chronic liar and anyone that she dislikes on TV, a doctor, neighbor or even in the extended family, she'll make up absurd lies about them. Things like saying a man is really a woman or a woman is really a man dressed up like a woman. Her mind is pretty sick. Most older people have hobbies, friends and interests. She has none. She doesn't know how to act in society or what is appropriate to say or do, even at home. We do all household tasks, cooking, etc., so she is not expected to do any chores. She doesn't know how to do basic things properly, from washing a dish/utensil/cup to cooking. She'll do step A and not do step B. She'll bring a basic package of virtually anything to us and say that she "doesn't know how to open it" and will claim that "nobody ever showed her how to 'open' packages in life". So she'll grab a fork or knife and rip it open to the point where it looks like a rat chewed it open. It could be a pack of lunchmeat, some cookies or whatever. Even stacking used dishes in the sink, she'll throw a big plate on top of some small bowls until it crashes down in the sink later. She literally doesn't know how to stack dishes.
Born in 1934, but doesn't know how finances or the world work, how inflation works, thinks prices will stay the same for 50 years, doesn't know how vehicles work, what they cost to maintain, what it costs to live nowadays, how basic things like the TV or microwave work and such. Even going to the bathroom, she wants to sit with the door halfway open and the light off in the dark. Instead of shutting and locking the door with the light on, she wants to sit in the dark and "clear her throat" when she hears someone coming to 'alert' them that she's in there. She wants to do the same in public bathrooms according to the daughter, who also says she 'sideways' on the toilet at home to the point where wood on the sink cabinet next to the toilet is considerably worn.
Her daughter can sit next to her on the couch watching an old game show with simple rules and my grandmother 'doesn't get' those simple rules and thinks it is somehow 'unfair' to the other players on the show. My grandmother is in this continual state of not paying attention to what is going on around her for some reason. Sometimes you can say something right next to her and she'll come back 20 seconds later and ask, "What did you ask?" because she heard it and wasn't listening. Or her daughter will tell her that there's some food in the top of the refrigeration and she'll go in there and fix some more and then say, "I don't know why I did that, I heard her telling me that, but I didn't pay her any mind" and things like that.
She paces back and forth hundreds of times per day from the living room to the dining room to the kitchen, then back. Usually stopping in each room to "look out of the window/wipe the window off" with a paper towel that she tears of between each window. She can go through a roll or more per day by herself just doing that. She'll claim there's fog on the windows and there won't be. She does it during the day and night. It's not cataracts because she had surgery on her good eye a while back (she said she splashed Clorox in her other eye when she was younger and can't see well out of it).
She does so many odd things like waiting until she hears someone go into the bathroom and then will get up running hanging onto her pants and going, "OHHH! I'm about to pee my pants!" and she sat on the couch for an hour doing nothing before that. It was only when they went into the bathroom that she got up. She does the same thing with the kitchen when she hears someone go in there and suddenly she needs to get in there.
She doesn't sleep well and will get up 'talking to him' during the night, having delusions, yawning loudly and doing all kinds of crazy stuff. Then she'll lie some days and say that she slept well. After pacing a lot, she'll turn around and say, "I don't know why I'm so tired" and want to take a nap during the day (which is perfectly fine). She'll stand there a few feet in front of the TV as if too anxious to sit down.
During the day and night, she'll be peeping around the corner trying to "see what we're doing in our room" and such. By far, my grandmother is one of the most odd and mentally "gone" people I have ever met. Her 'nervousness' means she'll knock cups off or not pick stuff up properly and drop it. It's usually because she sat it hanging off from a table and couldn't even do that simple task properly.
Things that are morally wrong and evil in life, she thinks the people that do them are good. Likewise, the people that try to do right morally and live a good life, she hates them.
What 'types' of mental illness(es) could be the cause of these things?