A judge sent Lindsay Lohan back to jail Friday after she failed a drug test, and the troubled starlet could stay there for nearly month.

Los Angeles Superior Court Judge Elden S. Fox did not set bail and Lohan was taken into custody immediately after the hearing at the Beverly Hills courthouse.

Fox set Lohan's next court appearance for Oct. 22. It will be Lohan's third jail stint for a three-year-old drug and drunken driving case filed after a pair of high-profile arrests in 2007.

Her previous stays at a women's jail in a Los Angeles suburb lasted 84 minutes and 14 days.

Lohan acknowledged failing a court-ordered drug screening last week in a series of Twitter postings.

Lohan arrived at the Beverly Hills courthouse Friday about 10 minutes before the hearing was set to start, wearing sunglasses and accompanied by her mother, Dina. Her father, Michael Lohan, arrived earlier.

It was the "Mean Girls" star's first appearance before Fox, who had said at a previous hearing he would sentence her to a month in jail for each drug test she skipped or failed.

The actress wasn't present for that hearing, which was held hours after her release from rehab.

Lohan has twice been released early to overcrowding, with her longest jail stay a 14-day stint on a 90-day sentence earlier this summer.

Lohan seemed to acknowledge an addiction problem after news of her positive drug test broke last week.

"Substance abuse is a disease, which unfortunately doesn't go away over night," Lohan posted on her Twitter feed last Friday. "I am working hard to overcome it and am taking positive steps.

"This is certainly a setback for me but I am taking responsibility for my actions and I'm prepared to face the consequences," her posts said.

The actress remains on probation for a reckless driving and two driving under the influence charges, all misdemeanors. Fox dropped two drug cases at a hearing in August during which he announced Lohan's release from rehab and set out a strict outpatient treatment schedule that included random drug screenings.

Fox has sealed Lohan's court file, but a source familiar with the case has told The Associated Press that the actress' failed test came roughly two weeks after her release from rehab.