Hi there ~
I understand your concerns. I strongly recommend that you take your son to a substance abuse
specialist doctor, who is usually a psychiatrist
or a psychologist
to get him the right treatment for the immediate acute care hospitalization may be needed and recommended. However for long term care a psychiatric rehabilitation
may be necessary. I hope you can also get a court order for treatment as it seems like he is putting his life at risk as well as the life of other through not letting them function in the right way. If you can get his friend to vouch for this in a court statement it may be helpful to have him get on the path of recovery for his own benefit, although without his will.
I hope this helps. Take care of yourself and have a lovely day!