Her lawyer, Tamar Arminak, addressed her mental health that year, only to state that she does not have schizophrenia and wished to keep her actual diagnosis private.
Months later, a tweet was posted to her official account stated she was diagnosed as bipolar and manic depressive. She later took to Twitter to claim a friend had taken her phone and posted the tweet.
That same year she famously tweeted she wanted Drake to "murder my vagina" and accused her father of abusing her before retracting her claims.
People were quick to put a psychological label on her behavior during that time, and Amanda admitted to Paper that she was bothered by the headlines about her mental health.
She insists her past behavior — including her wild tweets — were drug-induced.
"If you deny anything and tell them what it actually is, they don't believe you," she said. "Truly, for me, [my behaviour] was drug-induced, and whenever I got off of [drugs], I was always back to normal.'"
Amanda admitted that she is "really ashamed and embarrassed" by the things she said at the time.
"I can't turn back time but if I could, I would," she said. "And I'm so sorry to whoever I hurt and whoever I lied about because it truly eats away at me. It makes me feel so horrible and sick to my stomach and sad."
The child star said she didn't really like the taste of alcohol as a teenager, but she started smoking marijuana when she was 16. However, she added that she wasn't "addicted" or "abusing it" at that time.
In her early 20s, Amanda struggled with how she viewed herself, particularly after seeing her performance in the 2006 film She's the Man, a modern-day version of Shakespeare's play Twelfth Night.
The actress played a teenage girl who dressed in drag to pose as her brother, and she was unhappy to see herself with short hair and sideburns.
"I went into a deep depression for 4-6 months because I didn't like how I looked when I was a boy," she admitted, noting it was the first time she had ever told anyone that.
As she got older, her drug use progressed to molly and ecstasy. She also said she tried cocaine three times but "never got high" from it.
"I definitely abused Adderall," she said, recalling how she read a magazine article calling it "the new skinny pill" around the time she starred in the 2007 film Hairspray.
Amanda said she was able to get a prescription after going "to a psychiatrist and faking the symptoms of ADD."
According to the star, being high on Adderall and not liking her appearance led her to quit filming the movie Hall Pass in 2010. Although it was reported that she was let go from the movie, she said she "made a bunch of mistakes" but wasn't fired.
While on set, she said she would chew her Adderall tablets in her trailer because she thought she got more high that way. It got to the point that she was unable to memorize her lines.
Amanda recalled seeing an image of herself "on the screen and literally tripping out" because she thought her arm "looked so fat" before she left the film.
The actress had a similar experience in 2010 during a screening of her last film, Easy A, explaining that she "couldn't stand" her appearance in it.
"I was high on marijuana when I saw that but for some reason it really started to affect me," she recalled.
'I don't know if it was a drug-induced psychosis or what, but it affected my brain in a different way than it affects other people. It absolutely changed my perception of things.'
Amanda has been a student at the Fashion Institute of Design and Merchandising in Los Angeles, which is commonly referred to as FIDM, since 2014.
She will be receiving her Associate's of Art degree in Merchandise Product Development this month and plans to continue classes in January to work towards her Bachelor's degree.
Although she has an interest in designing a full line one day, she wants to revive her acting career first.
Amanda's story is a cautionary tale, and she warns about the dangers of gateway drugs because "certain things that you think are harmless, they may actually affect you in a more harmful way."
"Be really, really careful because you could lose it all and ruin your entire life like I did," she said, noting that she is done experimenting with drugs and doesn't miss them at all.
"When I was off of them, I was completely back to normal and immediately realized what I had done — it was like an alien had literally invaded my body,' she said. 'That is such a strange feeling."
