If someone is a drug addict, the chances are that he will either hang out with other addicts or nobody at all. Drug addicts are socially alienated because they are supposed to be a kind of social stigma. If you have a friend who has got into addiction then instead of running away from him you should help him out with your advice and moral support. He might have lost all his friends and maybe the sympathies of his family too. The most valuable thing that you can give to your friend, if he is addicted to a drugs, is your advice based on goodwill.