Andrea Yates believed that cartoon characters told her she was a bad mother who fed her children too much candy, a jail psychiatrist testified Thursday.

Dr. Melissa R. Ferguson, who talked to Yates the day after her arrest in the bathtub drownings of her five children, said the defendant suffered from a major depressive disorder and was psychotic, picking at her lip until it bled.

Ferguson was the first defense witness in the second murder trial for Yates, who has pleaded innocent by reason of insanity. She is being retried because her 2002 conviction was overturned last year by an appeals court citing erroneous testimony.

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Yates, who turns 42 on Sunday, would be sentenced to life in prison if convicted.

Ferguson, the former medical director of psychiatric services at the Harris County Jail, said Yates became upset at times during the interview but otherwise showed little emotion. She said Yates could not provide her children's birthdays, although Yates had given the information to a police detective the day before. Ferguson said Yates could have been confused because she had just been prescribed new medication earlier that morning.

She said Yates thought the television characters were berating her for giving her children too much candy and cereal.

"No, I do not believe she was faking her symptoms," Ferguson testified.

Prosecutors rested their case Wednesday after showing how Yates killed Noah, 7; John, 5; Paul, 3; Luke, 2 and Mary, 6 months, in the family's Houston-area home on June 20, 2001.

Defense attorneys have never disputed that Yates did the killing. They say she had severe postpartum psychosis and did not know the drownings were wrong.

Attorney George Parnham said Yates, in a delusional state, had a "prophecy" in which she thought that killing the youngsters was the only way to save them. She also thought that would somehow kill Satan, he said.

"That underscores how crazy she was on the day she killed her kids," Parnham said Wednesday outside the courthouse.

The defense must show that Yates meets the state's legal definition of insanity. That is, that because of a severe mental disease or defect, she did not know at the time of the offense that it was wrong.

Prosecutors cannot seek the death penalty this time because the first jury rejected death and authorities did not find any new evidence.