What a sad situation , you must both be desparately unhappy grandparents, worried sick about the lad.
However this is not your boy, he has parents who don't seem to be helping at all.Why?
The boy is not your responsibility, and you need to be very careful that he does not destroy your lives by his behaviour, and the relationship you have between you as well.
Yes , explore what help there is available, and discuss with him and his parents if you can, that way you are helping.
The bottom line however is what are they going to do, and what is he willing to do to help himself.?
You have to be totally objective in this matter and as detached as possible, he is nearly an adult , and you need to recognise that you cannot save every soul on the planet, however hard this may be to accept.
Sometimes people are on a self destruct mission and there is little you can do about it.
So get the information , pass it on to him and his parents, and remember that your own lives are not a dress rehearsal,and that you don't get to go round twice unfortunately.
Sincere good luck , will think of you.
Be strong please for your own sakes.
Brenda.