Better medicines were invented in the 1950's, 1960,s and 1970's and the population of state mental hospitals decreased from 550,000 to 110,000 from the 1950's to 1980's.
Far fewer patients were admitted and the closure of hospitals continues into 20000/s,
A cause of homelessness among persons with brain disorders was the states attempt at shifting the cost of treatment from states to federal government. In 1955 the federal gov. paid for 2% of the care of treatment.IN 1985 it paid 38%
These results are not the only reason but are important and are taken from the textbook "Nowhere to GO The Tragic Odyssey of the Homless Mentally" be E. Fuller Torrrey
Original: Homeless Mentally Ill: Some History