This is not as much a housing issue as it is a mental health and substance abuse issue.
See https://www.latimes.com/california/story/2019-10-07/homeless...
See https://www.latimes.com/california/story/2019-10-07/homeless...
Many homeless don't have mental health and substance abuse issues, but are just forced out of their homes on debt, etc. And of course some develop mental health (and sometimes substance abuse issues) after living homeless.