The deinstitutionalization acts (I think in the 70s?) put a lot of mentally disabled and ill people onto the streets, the government would no longer pay for their uptake as long as they didn't seem an outright danger to society. My brain is a bit foggy but I remember my psych professor in college talking a lot about this, and how it ended up that a lot of the homeless that live in the streets and continue to do so for so long are often mentally ill and disabled. Of course not all, there is no blanket statement that can be said one way or the other in my opinion, but shelters and services often have limits on how long a person can use them, so mentally disabled are kinda SOL unless they are considered bad enough or dangerous enough to be in a mental ward..

Just a something to consider. My great uncle received a head wound in WWII and had been somewhat mentally disabled since then. If he hadn't had his mother around to house and take care of him he may have been one of those out on the streets.

Just one perspective on it: http://www.interactivist.net/housing...ization_1.html