Unfortunately, the same bureaucratic garbage that results in ineligible people getting SSDI, also results in eligible people not getting it. My half sister has full-blown schizophrenia, and has been living in a makeshift tent near the Texas-Mexico border for decades. At one point she insisted she couldn't leave because she was guarding the border. My father has tried repeatedly to get her forced into treatment, to no avail. After much effort, he did persuade Texas authorities to haul her in for a forced psych exam, so an official diagnosis would be on the record.
After the obvious diagnosis was made (which it was quite illegal for the court to even tell my father), he figured he could get her on SSDI, and get her into some sort of residential treatment situation. Nope, SS is a federal program, and due to her "privacy rights", the state of Texas cannot divulge her diagnosis to the federal government. And of course there are no federal authorities with the inclination or authority to haul her in for another psych exam, until such time as she gets caught committing a federal crime. And of course she won't voluntarily divulge the information to the federal government, because she believes there's nothing wrong with her (except for the tracking devices that "they" planted inside her head, which "go off" when she passes through metal detectors, meaning she can no longer enter the post office to pick up mail from my father).
The people who invented and maintain this insane system should be first in line to get locked up in mental hospitals.
Seen this and similar situations. This is the true abuse of the mentally ill.
I thought about commenting along the lines of "at least someone is doing it!" But decided that comment might be offensive, so if it is I apologize.
Golly it's quiet here in chat.