While I agree that the mental health is vital, I disagree that it's of equal importance. Housing first has a winning track record, and bundling services can deter people from using either.
Someone might be just one restful night's sleep away from deciding that counseling isn't a trap.
It's worth noting that this is true for the vast majority of homeless, but the most visible contingent of homeless have severe mental issues that preclude a "housing first" approach.
Yeah, also when you throw in drug addiction. Housing-first really runs into issues with people who have destructive tendencies due to addiction or illness.
The track record of Housing First already includes people with drug addictions - it's been tested in real-world conditions versus existing strategies. This might sound counterintuitive, but "strings attached" only makes it worse.
Having no housing precludes keeping a proper medication schedule, record keeping, and a whole list of other things.
There's very little about mental illness that permanently frustrates sleeping indoors. Transitional housing, housing with shared bathing and kitchen facilities already exist.
That's not how the world works. Something needs to come first. You can't push medical treatment on people, the uptake is much worse than making available free housing.
Both are needed to be available, true. Work needs to be done so they don't depend on each other.
It's the only way to keep these people off the street, I dunno what else you want me to say. If you give them housing but no supportive services, they'll just trash it and then leave back to the streets. You can say that's not how the world works, but we'll need it to work that way for this small subsection of homeless people.
I think the issue is the term "mental treatment". Do you want social workers to come by once in a while? Of course: Have a talk, ask whether everything about the apartment is in order -- not an inspection, more the "if the drain doesn't work and you don't know what to do call us" kind of thing. But that's not therapy, it's at most psycho-sociological counselling. Therapy in most cases won't even work because there's the bulk of people's core issues is shitty life syndrome and there's no pill against capitalism.
Psychotic schizos (acutely or otherwise) should already be in an institution and on haloperidol and for the rest of us (yes you've stumbled across one on the spectrum) the same applies as for normies. There's no pills against the spectrum, either and yes we're kinda prone to shitty life syndrome on account of shitty society seeping through our barely existent self boundaries. Housing provides space and calm to work through the shit and please make doubly sure that social worker isn't conducting an inspection.
You can't push medical treatment on people, the uptake is much worse than making available free housing.
And that's IMO part of the problem, combined with some pretty bad history regarding domestic use of asylums etc.
You can't give somebody who's had a mental break a house/apartment/etc in the general population no-syringes-attached and maybe a once-a-week drop-in and expect things to go ok. That just results in places getting attacked with drug-fueled parties etc, and it's not particularly great for the neighbors.
There is group housing, but again if you stick an unrepentant addict who has mental issues in with people who are trying hard to recover, that'll negatively influence their living situation and mental health situation of those around them.
So... first-start housing needs to be in a controlled or semi-controlled environment that can allow people to recover when they're not in a good enough mental state to make sound health/life choices. You can't be no-strings-attached without it impacting those around them and their own ability to recover, and you just end up with a shit hole (literally in many cases) full of junkies, dealers, and people screaming at walls.
As those who are willing to improve things do so, and gain the faculties to make that decision, the housing situation and independence can change as well, but the care, housing, and healing need to go hand-in-hand with some basic ground rules for the good of all.