The 24-year-old actress was discharged from a suburban Los Angeles jail about 1:35 a.m. Monday. She served 14 days of a 90-day jail sentence for violating her probation for a 2007 drug case.
CBS Radio News correspondent Steve Futterman reports Lohan left the jail through a back or side entrance, avoiding the throngs of media amassed near the front door.
Futterman says Lohan's departure was announced by a spokesman for the sheriff's office, who said the star was met by members of a drug rehabilitation center and quickly whisked away for treatment.
The "Mean Girls" star's release doesn't end her legal saga though. She now must go to an inpatient rehab program.
"Early Show" National Correspondent Hattie Kauffman reported Monday Lohan is supposed be treated for three months at the UCLA Medical Center in a live-in rehabilitation center -- not the posh seaside rehab center that offered surfing and yoga speculated about earlier.
Kauffman said, "Apparently the judge nixed that idea."
Dr. Reef Karim, an addiction specialist, told CBS News in rehab Lohan will likely be "doing chores all the time."
He added, "You're watched all the time, you're drug-tested all the time."
Kaufffman pointed out TMZ reports that Lohan will be treated for bipolar disorder and an addiction to crystal meth. Kauffman said Lohan's attorney denies the report, telling RadarOnline, "It's a fabrication, 100 percent."
Lohan had been in a sequestered unit of the women's jail since July 20. The facility has also housed stars such as Paris Hilton and Michelle Rodriguez.
Lohan had no phone, computer or cigarettes. Reality tv star Alexis Neiers, who was jailed for her role in the celebrity "bling ring" robberies says she could hear Lohan crying in the next cell.
A judge in Beverly Hills determined Lohan violated her probation by missing seven weekly alcohol education classes since December.
The question will now be whether the talented actress with a long history of drug and alcohol problems can really turn her life around.
But Lohan's probation report lists five powerful drugs currently prescribed to the actress including Adderall, Dilaudid and Zoloft.
Karim, said, "They're gonna require a lot of time, a lot of energy and a good doctor to help somebody get off those medications."
Lohan's expected to foot the bill for treatment -- $10,000 to $15,000 a month. If she violates any rules, Judge Marsha Revel could send her back to jail.
Kauffman reported Lohan will have a strict routine starting at 7 a.m. every morning. She had requested a 24-hour break before reporting to the facility, but the judge ruled she report directly to rehab. When finished, she will undergo random drug and alcohol testing for another 12 months.
Dr. Dale Archer, a psychiatrist who specializes in chemical imbalances in the brain and personal responsibility, told "The Early Show on Saturday Morning" that Lohan can turn things around if she separates herself from certain people -- perhaps even her family.
"If she were my patient, I would say, 'Look, no work for a year; your sobriety is more important than family, friends or job, because if you don't say sober, you will lose all of those, and you may lose your life as well,'" said Archer.
On "The Early Show" Monday, Dr. Harold Koplewicz, a child and adolescent psychiatrist and director of the Nathan S. Kline Institute for Psychiatric Research, said its going to be "a long haul" for Lohan -- particularly if she has a psychiatric illness and substance abuse issues.
"We should know that bipolar disorder is a very serious illness, about 1 percnet of the teenage or young adult population. And, unfortunately, it's so serious that it has the highest suicide rate of any psychiatric illness, as well as having very high rates of substance abuse," he said.
He explained, "So, when you have this illness, you are periods of time, sometimes as long as two weeks, where you're as high as can be, you are hypersexual, spending too much money, and your judgment is so poor that you're putting yourself at risk. And then when you come back down to baseline or even lower, you are so, so crazed that you feel so terrible and so irritable that you start to self-medicate. These illnesses have been around for years, Joshua Logan, Dick Cavett, Patty Duke. Often very creative people have these illnesses but without lithium or other kinds of medicine to keep them stable, they really can't function."
Koplewicz said someone who two problems have to get clean first.
"Basically, the first few weeks, first 28 days, so to speak, is getting someone clean, understanding why they need those medicines," he said. "Can they sleep in can they concentrate? Why they crave something? And being in a contained, secure environment. Then looking at their symptoms. So, do they really have this psychiatric illness that has been masked over by all these drugs they're taking."
As for the UCLA facility where Lohan's to go, Koplewicz said it has the expertise in mood disorder and substance abuse that may be necessary in Lohan's case.
But can Lohan get started on the road to recovery in just 90 days?
Koplewicz said it's an "individual thing."
"It seems most patients with these disorders have a lot of trouble accepting them," he said. "Sometimes they have to really hit bottom more than once to say, 'I have something wrong with me. Think about it: Most teenagers and young adults want to be just like everyone else. The last thing they want to do is say, 'I'm sick, I have to take a pill the rest of my life.' This is a hard one, and I think it's particularly difficult if you're a movie star and everyone's watching you. It's hard enough if you just have to deal with your family. But when the world's watching, it's so much more complicated."