This is a really tough question...to me, it's time to approach someone about their addiction when I feel like I know enough and am strong enough to be supportive and deal with all the emotions and anger and other issues that are a part of dealing with addiction. If I'm not ready to deal with the fact that they have a addiction, it doesn't seem fair to expect them to be ready. Visiting a support group for family and friends of addicts can be really helpful in figuring out the right time and the right approach.
I think confronting someone about their addiction is something you do almost as much for yourself as for them, because addiction affects more people than just the addict.
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