Andrea Yates, 36, who confessed to drowning her five children one-by-one in a bathtub in her Houston home, has been charged with capital murder. Attorney George Parnham said he would likely seek an insanity defense for his client, whom he said was in a "very deep psychosis."

DAVID ASMAN: Police say Andrea Yates confessed and now a Houston TV station reporting Yates is pregnant again. Dirk Johnson, wrote about this bizarre case for "Newsweek" magazine and he joins us today. Thanks for coming in, Dirk … Let's talk about this, have you been able to confirm for yourself indeed these pregnant again?

>> No we haven't. We've talked with her lawyer. Who said that it is not clear but apparently testing will be available later this week.

DAVID ASMAN: This is a suspicion at the moment but not based on any test that's been done.

>> As far as we know.

DAVID ASMAN: Okay. Now, initially, last week, as events turned very quickly on this case, we heard a lot about postpartum depression, about how that was the cause of this. We're hearing now she appears to have been a lot sicker than that. An anti-psychotic drug which she got off of shortly before the murders took place. But the bottom line is this was much more than just postpartum, wasn't it?

>> Well, it would seem. She was in fact, taking haldol which is an anti-psychotic medication and she was taken off of that, in hindsight and unfortunate step. But she was suffering from some very severe mental disturbances.

DAVID ASMAN: …I …heard before, which is that apparently she had shown signs of mental illness before she had heard her -- had her first child. What signs were they?

>> That's not clear. There were some vague hints by one of the family members that that was the case. Although her mother said it was not until the birth of the fourth child she started to … troublesome signs in particular attempted suicide over two years ago.

DAVID ASMAN: Over how long a period was it clear that she was really sick?

>> She for the last two years, on and off, there had been terrible problems. Although her husband said at one point early on the medication seemed to snap her out of it, he said.

DAVID ASMAN: And you know we don't mean any more pain for her husband than he already has experienced. Just unimaginable, frankly. ... How could he have entrusted his psychotic wife with children?

>> That's a question a lot of people have raised. In fairness, his own mother, Andrea Yate's mother-in-law came down to help out. But indeed, five young children at home, home schooling, in addition to that, she was taking care of her father who had Alzheimer's for seven or eight years … bathe him and feed him and he died in March. And she continued to spiral downward after that.

DAVID ASMAN: In fact, suggest that the death of her father was really a trigger that seemed to make her much worse?

>> The family members said there was a marked turn for the worse after the death of her father.

DAVID ASMAN: Now, this is a question … we had the psychiatrist for Susan Smith, another women accused or convicted of having killed her children, he said that, in fact, these drugs, that did seem to work for a while, actually had no effect curing the psychosis ... The minute somebody goes off the drugs, all the reasons that this illness began flood to the surface. Which is your interpretation?

>> Well, it's hard to know. More extensive medical testing will be done right away...

DAVID ASMAN: … apparently her family was under the illusion perhaps encouraged the drugs could fix the problem.

>> They must have been. She had apparently agreed recently to end talk therapy, resisted that until lately … her family members say.

DAVID ASMAN: Now, talking about the character of Andrea, her mother you describe her mother as saying she was just a really a perfect child, she was -- she was very well liked by everybody. She performed extremely well at school. After getting married, as you mentioned, not only took care of father sick with Alzheimer's but was friends and helpful to neighbors. I mean, she seemed to be doing everything for everybody perhaps except herself.

>> One of the neighbors of the parents, said that he couldn't help but notice how she seemed to struggle. She had simply so much going on she was almost obsessed to absurd levels with trying to help everybody. She would, heavily pregnant with children in tow, get up on the ladder and put the decorations in the trees at Christmas time. Run to the neighbors to help them. Literally return around the kitchen to feed her own parents as the plate grew cold. It was clear she was under strain.

DAVID ASMAN: To say the least. This is a question the last question, you've delved into her case extensively and in the another case … Christina Rigs she was executed for that crime, the prosecutor said the following about what might have motivated the women: This woman was found guilty and was executed. What do you think the bottom line is here?

>> Well, the prosecutors say it's too early to talk about the death penalty. Traditionally courts have been more unlikely to invoke the death penalty when the husband is supportive. Although there has been a lot of speculation if you don't use the death penalty a case where five children were killed, when would you use it?

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