Paris Hilton is "teetering on the brink," according to TMZ.com — on the brink of what, TMZ does not say, but the Web site's further reporting does not paint a swell picture of the starlet.

The hotel heiress hasn't eaten or slept since arriving back in jail Friday, according to the Web site. And she's now taking psychotropic medication, TMZ reported.

TMZ sources described Paris as "fragile," "despondent," "a train wreck," and "sullen and withdrawn."

Click here to read the TMZ report.

In a room by herself in the medical ward of the Twin Towers detention center, Hilton is crying and praying, and is extremely withdrawn, according to TMZ. A sergeant stands at her door at all times.

Also, it was believed she was undergoing medical and psychiatric evaluations to help determine the best jail to keep her in as she serves the rest of her sentence. TMZ reported she met with her shrink for more than two hours Saturday morning.

The hotel heiress, in tears and screaming for her mother, was taken to the downtown jail Friday after a judge ordered her back there, ending her brief stint under house arrest at her Hollywood Hills home. A day earlier, she was escorted from the courtroom shouting "It's not right!"

On Saturday, Hilton released a statement in which she said she had informed her lawyers to not appeal her case.

"Today I told my attorneys not to appeal the judge's decision. While I greatly appreciate the Sheriff's concern for my health and welfare, after meeting with doctors I intend to serve my time as ordered by the judge.

"This is by far the hardest thing I have ever done. During the past several days, I have had a lot of time to reflect and have already learned a bitter, but important lesson from this experience."

"As I have said before, I hope others will learn from my mistake," she wrote.

Hilton's lawyers sought to keep her out of jail on grounds that the 26-year-old was suffering an unspecified medical condition. Superior Court Judge Michael T. Sauer suggested that could be taken care of at jail medical facilities.

Los Angeles County sheriff's spokesman Steve Whitmore declined to discuss details of Hilton's case Saturday, including the state of her medical evaluations, citing laws against revealing such information on inmates.

"All I can say, as with all the inmates in this facility, they are monitored continuously," Whitmore said.

Although Whitmore would not discuss Hilton's condition, Sheriff Lee Baca indicated at a news conference Friday that it was psychological.

He said she arrived at her original jail with a condition he had not been apprised of and that it immediately began to deteriorate to the point that he feared for her safety.

"When you're talking about psychological problems it's far more complex and it does require a more complex medical approach," Baca said. "We didn't have all of our information."

When she went to Twin Towers, Baca said he was placing Hilton in a "better facility for her condition, meaning one that has a more intense form of medical support." He said she would be kept under close watch to ensure "that there isn't anything harmful done to herself by herself, which is a great concern to me."

Whitmore said she will be there at least through Sunday.

Twin Towers is equipped to treat acute medical and mental health needs, although inmates in need of more serious attention are moved to a hospital. About 40 inmates are housed per floor, and most of the rooms are designed for one patient at a time.

Hilton is in a room Whitmore described as a little more than 100 square feet, with a toilet, sink and "a sliver of a window."

It is roomier than the cell she had at her first lockup, the Century Regional Detention Center in Lynwood, a gritty city south of Los Angeles. That cell measured only 96 square feet.

Between 10 to 20 sheriff's deputies, doctors, nurses and other medical personnel are on each floor to monitor inmates at Twin Towers, Whitmore said. The staff does not use cameras to monitor rooms.

Female inmates are allowed visits on Sundays and Fridays.

Because she surrendered to authorities late Sunday night after attending the MTV Movie Awards and then fitted with an ankle bracelet before being released to home detention on Thursday, Hilton was credited seven days for her sentence. With time off for good behavior, she could be released in a little more than two weeks.

Hilton's path to jail began Sept. 7, when she failed a sobriety test after police saw her weaving down a street in her Mercedes-Benz on what she said was a late-night run to a hamburger stand.

She pleaded no contest to reckless driving and was sentenced to 36 months probation, alcohol education and $1,500 in fines.

In the months that followed, she was stopped twice by officers who discovered her driving with a suspended license. The second stop landed her in back in court where she was sentenced to jail.

The Associated Press contributed to this report.

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