I noticed you didn’t mention bipolar disorder as one of his diagnoses. He sounds kind of bipolar to me (I’m also diagnosed with BPD, Type II). Might be worth it, if he’s willing, to be evaluated for BPD as it would indicate a different approach to treatment. Although you’re right that at 19 he is considered an adult and cannot be forced into treatment, you could maybe get legal guardianship over him, so that you could sign him into a hospital if you (and a doctor) think that hospitalization would be beneficial. Here’s an article about guardianship and mental illness – http://www.specialneedsalliance.org/guardianship-and-mental-illness/ that might be helpful. If Russell Barkley is right about the 30% on average developmental delay in the brains of people with ADHD, your son at 19 is more like a 12-13 year old in terms of judgment and decision-making abilities. That’s something to think about too, when considering how much tough love you want to incorporate. Not that it doesn’t sound like he needs some, but keep encouraging him to seek treatment. From a personal perspective, I know that when in the grip of my illness, I do and say things and make decisions that I very much regret, and would never do when all the neurotransmitters are working correctly – and I don’t have the added burden of ADHD.