I have someone in my life who is like a son to me. Recently he has been walking a path which I believe in my heart might be a dangerous one, but I don't want to overreact. He's into smoking weed and seems quite comfortable using. I have been telling him to quit the habit but he insist he's not addicted to smoking and that it's just a phase. I worry that he might become addicted and often ask myself at what stage is it considered an addiction. I know that marijuana plays a big part in today's generation and I know only too well that it's being embraced the world over. Should I just leave it alone and trust that at 25 he knows what he's doing? I get confuse at times.