Thanks so much Amber22 for your great thoughts. Main problem is that despite being a sensitive, smart, creative young adult, and his recognition of his adhd, he can't/won't engage with any support or take responsibility for learning to live his own great life with adhd.
He insists he can handle his adhd without any support, other than self-medicating with cannabis.
His adhd means that he is impulsive, reckless, chaotic, makes poor decisions leading to constant serious problems.
We've done family therapy, and he's had a couple of detox stays in hospital under supervision of his psychiatrist at the time. He's seen psychologists, psychiatrists and GPs, with a support person.
He can't hold down a job due to poor performance, lack of attention and responsibility.
It's like watching a slow train wreck. Maybe when the final crash happens, he will receive the help he needs, even if it's in prison, where so many others with untreated mental health issues end up. I desperately hope it's not a fatal accident involving him or someone else.
If we tossed him out from all the love and support he receives here at home, he would just go sleep in car or park.
If this is all typical of adhd, I still have no idea how he will access all the help and support available.