How long can I let my ex-addict son stay at home?

You ask if after three years is your son ready to be pushed a bit? While I agree with your premise, that staying at home might be stunting his growth as an adult, I cannot definitively say what is best for your son. I will, however, give some guidelines.

I my opinion, the goal of the job of being a parent is to achieved when the child becomes an independent adult. Not because it is good for the parent, rather because that is healthy for the child. (I have six children. Four are independent adults, one is almost there, and one might get there with outside professional assistance.) Sometimes it is easy to achieve and sometimes we go through hell to get there. We certainly do not choose the challenges placed before us when charged with helping another human being into adulthood.

You son might be no bother to have around. It is certainly less challenging for everybody to keep the status quo. Even if your son is really ready to be pushed, there is no way of predicting how he will react to the challenges of being an independent adult. So consider the worst case scenarios: he can stay dependent for as long as you can stand it or risk (in the worst case) a few years of hell on the way to becoming independent.

If that were your only two choices, what would you choose?

But those are not the only choices. You might push him to be more of an adult with professional assistance. I think that is the only reasonable path. Here's why: you love him and do not want to see him hurt. He might get into trouble on the way to becoming a healthy adult. You will want to save him more than anything else in the world because you can't imagine going through what you've already been through. But if you do save him he might learn that the bottom line is that he doesn't ever need to grow up. That is the essence of "codependency." Since it is a real expression of love and concern, it it the single most dangerous force for families that want their loved one to get better. Breaking codependency is completely counter-intuitive.  Which is why you need professional help and guidance, even if you are completely aware and knowledgeable about what you son needs.

High end treatment centers begin their process by not allowing their patients any contact with their families for at least 45 days. The reason is that the basic idea of adulthood is that the adult will take care of him or herself without needing someone else to be responsible for the consequences of his or actions. That cannot happen at home. So, at some point, you son will have to be pushed to be more independent.

On the other hand, your family has its own particular needs and structures. He has his own quirks. Does he talk about being independent? How is he? Are there siblings that influence the picture? Are there other health issues in the family? Is asking for rent or doing his own cooking and cleaning possible in your family? What is his social life like? How fragile is he, or you, or your wife? does he have skills or interests? There are myriads of questions that need to be considered when designing a plan to help your son, and since it is not the culturally normative path each step should be thought out.

So the answer really is: Done properly you are 100% right (with a realization that it is still a path that will have ups and downs) and done without help and planning you wife is 100% right (although at some point it is likely to backfire because he remains immature.)