How does Europe deal with this? I'm not aware of wide-spread forced institutionalisation. Are the problems dealt with before spiralling to full-blown homelessness and mental health issues?
Europe didn't get the opioid crisis. It is a "uniquely American problem" that we created by over-prescribing highly addictive opioids and then kicking them off the prescriptions once it became clear that they were addictive. That drove many people onto illegal drugs like heroin.