My son is 16 years old and seems to have become addicted to weed. I’ve begged him and tried to educate him but he won’t listen. His mood and demeanour have changed and he is no longer recognisable. I don’t give him any money but he has a part time job. I can’t just sit back and watch him get deeper into this. He won’t go and speak to anyone and laughs at me when I get upset. Please tell me how I can stop this. He goes out with my permission.