Troubled actress Lindsay Lohan has finally agreed to undergo Adderral-free rehab treatment in a new facility after realizing that she had been consuming the drug to treat Attention Deficit Hyperactivity Disorder (ADHD), which she apparently didn't have.

Lohan, 26, threw tantrums over the past three months for not being allowed to take the drug in previous rehab centers. Earlier this month, she showed bad temper at the Betty Ford clinic after they refused to allow her to take Adderral. She threatened to quit rehab, unless she was permitted to access the restricted substance.

Lohan told friends that she was diagnosed with ADHD at a young age and the prescription drug was essential for her normal functioning. However, her new doctors at Cliffside Malibu in California believe that she was probably misdiagnosed and doesn't actually have ADHD.

Adderral is popular among young actresses in Hollywood because it has the ability to control weight. It is also a highly addictive drug and one of the most abused substances in Tinsel town.

Apart from Hollywood actresses, teenagers are also known to pop Addrell to pull up all-nighters. According to Senator Chuck Schumer (D-N.Y.), approximately 64,000 students pop Adderall or a similar drug in New York City alone.

"If you're using Adderall for any reason other than for attention deficit disorder, you're basically using speed," Dr. Samuel Altstein of Beth Israel Medical Group said. "It's vastly overprescribed, overused and misused by a lot of people."

Altstein warns students about negative effects of such pills. The long-term abuse of these drugs can lead to depression, anxiety, loss of appetite, sleep troubles, dry mouth, diarrhea, dizziness, psychosis and heart failure.

Doctors treating Lohan believe that stopping her from using the substance was necessary for her treatment.

Currently, the 'Mean Girls' star is in the process of completing a 90-day court-ordered treatment following a reckless driving case in Los Angeles last year.

Doctors feel that there is still a lot of work to be done with Lohan and suggest she extends her court-ordered rehab stay.