I had one of those... he lost his job, dropped out of the local
community college, lost his girl friend and spiraled into
depression. I think that I "bugged" him every day asking him
what was the matter.
He finally smapped out of it... made a decision to go into the
merchant seamen (that was left field) and finally at my urging he
went to put in applications at the local hospital. I told him he
shouldn't care what he works in, he just needed a job. He is
working in house keeping, got his girl back and she has encouraged
him to go back to school. So, he is now looking into getting
into one of those computer networking type of classes/degree
programs.
I think it just runs in cycles. My Advice: Stay on him daily.
"how's it going" "Have you made any decisions yet? " "Take out the
garbage." "Clean the bathroom." "Are you looking into working at
the hospital, school system, city system, where ever?"
The point is for you as the mom to be actively in his life
whether he wants it or not.
Just my 2 cents.
(And my son will be 23 in June)