In the case of Andrea Yates, it's difficult to say what would have been the optimal form of treatment for her. There were a lot of different influences at play during her life, many of which may not even be documented. With the given information about her, one could conclude that her lifestyle could have been greatly changed if the social aspect of her particular psychology were addressed first and foremost. Given her religious affiliation and encounters with Michael Woroniecki, it's likely that the influences of religion weighed heavily enough on her to alter her personality on a psychological level, and in turn, biologically. With only the given information on Andrea to reach a conclusion on optimal treatment options, it's hard to judge when in her life would have been the most beneficial. Earlier would be better, but it's possible she was perfectly stable until a certain point. It seems that in the early stages of her downward spiral she seemed open enough to want to get better, but upon returning to her normal life, quickly relapsed. Given this assumption, if she had simply stayed actively involved in her treatment process, it's likely that she could have taken a much different path; And that's the biggest error in her original treatment run, there was seemingly no follow-up, and no enforcement. Persistence aside, Andrea should not have been allowed to continue having children, for the possibility of her acute depression being onset by her pregnancy. The other action that should have been taken is a semi-radical relocation, to somewhere with proper living conditions and less religious overtones. Of course, it's also possible that Andreas first mistake was marrying Dusty, as it seems the majority of her problems arose after marrying him.
In the end, I think the biggest fault in andreas treatment was the lack of conviction on multiple parts, namely hers, to want to improve her condition.
