As you say, he is probably clinically depressed. Maybe even a stronger psychological problem. Beyond the reach of TLC. Problems that are not your fault are his parents' fault. He has wrapped himself in a blanket of blame and he is willing to destroy everything around him rather than let go of the blanket.
My husband and I were able to reach that existential moment through the Retrouvaille program. Unfortunately, that didn't work for you. Woog is right. There is no alternative to him getting help from a professional. He can do it now while he still has people who love him around him, or he can do it later, when all that is gone.
When my son was depressed and doing alcohol and drugs, I took him to a psychologist. He walked out of the session. The psychologist called me in and told me, "it doesn't matter. Eventually he will get the help he needs, either in jail or in a mental hospital." He was right. My son ended up getting help in both places. It could have been easier, but that wasn't his plan. He had to crash and burn.
