Lindsay Lohan reportedly began her 90-day rehab stint at UCLA’s Resnick Neuropsychiatric Hospital today…and it’s so strict that she’ll FINALLY get the help she needs!

Lindsay Lohan was meant to check in to the easygoing Morningside Recovery rehab facility in Newport Beach, Calif. this week – but at the last minute, Judge Marsha Revel changed her mind and placed the young actress at UCLA’s hardcore Resnick Neuropsychiatric Hospital instead. One insider tells exclusively why Lindsay has a shot at actually beating her addiction now that she’s being placed in a seriously strict facility.

“UCLA is not going to take Lindsay’s bullshit,” LA-based addiction expert Marty Brenner — who’s with the Lohan family in the past — says, explaining, “During her other times, she RAN drug rehabs because of her celebrity status. This facility is a hospital. It’s much more medically based.”

According to the hospital’s website, laptops and cell phones are not allowed for privacy purposes and phone calls can’t go over ten minutes. Although iPods ARE allowed, they must be locked up and have to be checked out from the nurses. Additionally, visiting hours are stricter and there are no field trips from the facility…a far cry from Lindsay’s first assigned rehab facility, Morningside Recovery, where she was allowed shopping trips and weekend visits with friends.

“This is strictly therapeutic. At the other place there were no boundaries,” Brenner says. “People keep asking if Lindsay’s bi-polar, but the truth is, we won’t know until she gets off all the meds she’s on. Nothing can be diagnosed until she’s completely off everything, which will probably take a couple of weeks.”

As far as allegations that the Mean Girls actress is addicted to methamphetamine, Brenner has his doubts.

“If Lindsay was really addicted to meth, she would have been broken out. She would have lost a ton of weight quickly. The symptoms of meth show up right away,” he explains. “People are basing all that off her behavior, but I don’t think she actually showed the physical signs of meth addiction. I can’t really answer that. It’s all hearsay.”

Lindsay will remain in the court-ordered rehab for the next 90 days. Upon being released she’ll be under probation with random drug testing for a year.