Russell Yates testified Thursday that his wife never told him about the voices she heard or the visions she saw.

Andrea Yates, 37, claims that the delusions led her to drown the couple's five children on June 20.

"She kind of described it as a dark period, that she was in a dark place," Russell Yates said, referring to his wife's two suicide attempts after the birth of their fourth child, Luke, and two years before the killings.

"At the time, I didn't think she was dangerous, none of us did," he said.

Later Thursday, Andrea Yates' best friend testified she had begged Yates' husband to seek help for her.

"A couple of times I called her husband and I was crying and sobbing: 'She needs help now. Now! Not next week!'" Debbie Holmes said. "I was very frustrated at the lack of care I thought she was receiving."

Holmes, who befriended Andrea Yates more than a decade ago when both worked as nurses, said the woman's mental condition deteriorated after the birth of her fourth child in 1999, and worsened the next year after the couple's fifth child was born.

"She had gotten worse and worse," Holmes testified. "She was so physically ill. ... She wasn't eating or drinking anything."

Holmes said that when she visited the home last spring, Yates was dirty and paced through the house.

The Houston mom has confessed to drowning the children but has pleaded not guilty by reason of insanity. She is charged with killing three of the children and could face the death penalty if convicted.

On his second day of testimony, Russell Yates again smiled at his wife as he entered the courtroom.

He testified that on the day of the drownings, Andrea Yates was eating cereal out of a box as he left for work at the Johnson Space Center.

The testimony was far less emotional than Wednesday's session, when Russell Yates tearfully described his wife as a loving mother whose mental problems worsened in the months before she drowned their children in a bathtub at their Houston home.

Her husband has testified in his wife's defense, attempting to describe her loving support of the family while underscoring her mental illness. Her attorneys hope to demonstrate she didn't know right from wrong at the time of the drownings and therefore cannot be found guilty of capital murder.

Yates on Thursday described the family's aversion to "social integration." He said the couple wanted to live a simple, traditional life.

"Man is the breadwinner and woman is the homemaker," he said. "It's the way it's been for years."

Russell Yates also went into detail about the family's relationship with a traveling preacher, Michael Woroniecki. Yates said the preacher believed it is too late to undo society's damage to a child by age 14 or 15.

Defense attorney George Parnham asked Yates what the minister meant.

"I think what he's saying, it might keep them from following the Lord long-term," Yates said. "The vast majority of people are going to hell, that's what he might write."

Earlier, Yates read a portion of a newsletter the couple received from the preacher. The quoted portion spoke of a mother who was driven crazy by her children.

"On the day of judgment, she will have no plea," Yates read Wednesday. No explanation of the newsletter's relevance was given by the defense.

Earlier in the trial, a psychiatrist who interviewed Andrea Yates in jail said the defendant believed she had been marked by Satan and that killing her children was the only way to save them from hell.

Yates also told jurors his wife suffered from severe postpartum depression following the birth of their fourth child in 1999 and was under the care of a psychiatrist following the suicide attempts.

After his wife's first hospital stay in 1999, Russell Yates said, he moved the family from a converted bus in which they had been living -- they had bought it from the preacher -- into a house in southeast Houston.

"At the time, we didn't know whether she'd ever recover," Yates testified. "But if she did recover, there would be more space for home-schooling."

He added it was "unthinkable" that he would ever send their children to school.

"The social integration that the world claims is so essential is exactly what we need to protect our children from," Yates said.

Andrea Yates soon became pregnant with Mary, who was born in November 2000. Yates said his wife's depression returned and it grew worse after the death of her father last March.

He said his wife was treated by psychiatrist Dr. Mohammed Saeed but didn't seem to improve. Russell Yates said he and his wife returned for treatment June 18, but the doctor didn't put her back on an anti-psychotic drug and changed her prescription.

Two days later, Andrea Yates called her husband and told him to hurry home because something had happened to the children.

Andrea Yates is charged with killing 7-year-old Noah, 5-year-old John and 6-month-old Mary. Charges could be filed later in the deaths of Paul, 3, and Luke, 2.

The Associated Press contributed to this report.