The 27-year-old actress admitted to Oprah Winfrey that her problems began after she found fame as a child, reported Contactmusic.
"When I moved to LA after filming Mean Girls, I was 17 or 18. I was around people so I wasn't lonely, and I didn't pay close enough attention to people being around for the wrong reasons. I was making too much.
"I wasted so much money; I was living at a hotel, and I had an apartment. I wasn't really being guided. I didn't think about it, and I didn't listen to my family when they told me, 'Come back to New York,'" she said.