The 24-year-old "Mean Girls" and "Freaky Friday" star has been battling an addiction to drugs and alcohol for several years.
She has repeatedly gone to rehab, then suffered relapses, and has been in and out of jail for violating her probation in a 2007 driving under the influence conviction.
E! News said she is expected to remain in rehab this time until her next court hearing Oct. 22.
2014: The Year in Music [PHOTOS]