About 10 years ago i was doing coke so much i did,nt know what day it was and i got so bad i could,nt tell day from night and thats what woke me up and made me realise i did,nt need it .Sounds like a perfect time for an intervention with you all round there. Hard things to go through I imagine but allegedly one of the most effective methods of getting an addict to realise what they are actually doing and to help them.
http://drugs.homeoffice.gov.uk/drug-interventions-programme/
I was lucky i had good friends who helped me one even took me to a childrens ward where the children had cancer and said to me the children in here don,t have a choice and i did boy did that wake me up.
I guess i,m saying be there for him and talk to him and make him realise that life is the best drug he can have.