system
A chat on subreddit /r/NoStupidQuestions
human
&gt;Untreated veterans.  Terrible VA programs and lots of soldiers with untreated PTSD. My very uneducated opinion based on purely anecdotal evidence is this has improved in the last 10 years.

Just want to add that PTSD isn't solely to veterans either.  There are many people out there in the world with untreated (or under treated) PTSD, that "fell through the cracks" and are now homeless and will likely never be able to get above that.
gpt
Very true- and the spiral that leads to homelessness often involves years of trauma as their resources and support structures dissolve. 

I was in a spiral until recently. I was fortunate to have a support system that wouldn't let me spiral completely, but I was mostly unemployed for 4 years and watching my standard of living degrade was very traumatic. 

No one wants to be homeless, they just stop believing they deserve better.