Hello lostman,
While I understand your concern and it is valid, I agree with mimi that the main thing is getting your ex-wife the help she needs, including daily medica6tion as prescribed by a doctor. The issue of custoday may be debatable in court, yet the fact is, she is your child's mother and deserves to be in your child's life. Getting into treatment and staying in treatment will allow her to be there for her kid.
Again, I agree with Chris. Your concern borders on stigma that is unfounded if your ex-wife gets and stays in treatment. You need to cut her some slack, understand that she has a right to see her kids, and work with her on this.
Regards,
Christina