Troubled Hollywood star Lindsay Lohan voluntarily checked into an in-patient rehab facility in Southern California on Monday.
The move comes after the 24-year-old admitted failing a court-ordered drug test last week.
"Substance abuse is a disease, which unfortunately doesn't go away over night," she wrote on Twitter.
"I am working hard to overcome it and am taking positive steps."
She was released from jail last Friday after winning an appeal to be granted bail following the failed test.
Her estranged father Michael – himself a reformed addict – had urged his daughter back into treatment over the weekend.
He said that he was praying that her lawyer Shawn Chapman Holley "does the right thing and advises her to go right into rehab now, and show the judge she's serious.
"Because in 30 days when she goes back before the judge he can do whatever he wants".