They’ve always been there but people kept them at home or they put them in special ed. I remember when I was around 18 and had never heard of Alzheimer’s, and I don’t even know if they were diagnosing it back then. On Christmas day a woman showed up at my brother’s house. It was obvious that she was confused and we couldn’t get any information out of her. We called the police and her family had already called them so they just came and picked her up and took her home.
Yes, these folks have always been with us.
It seems they are much more prevalent in recent years.
Another commentator here has pointed out that they’ve been ‘mainstreamed’ into society ... that is, shoved (or pushed, or let) out of care facilities.
SO, that may help explain why they seem all the more in evidence.