I have not read this entire thread because I have to get ready to go to a T appt. What Andrea Yates did is as horrifying as any event in life can be. Obviously, there are no words to precisely describe the egregious action she took.
Do I believe that someone can be in a psychotic state as extreme as she was in? Yes, I do believe it. I suspect that paranoid behavior to such an extreme is extremely rare, but I understand how a person might become unable to resist acting on extreme, severe, intractable terror.
I feel anxious all over my body when I think about what that woman did. I cannot, however, point a finger of doubt at her anymore than I would want someone to doubt my own mental illness.