The 27-year-old actress was placed under an involuntary psychiatric hold in July, but she has now completed her inpatient treatment and is recovering at her parents' home in Los Angeles.
Amanda's mother's lawyer, Tamar Arminak, released a statement saying: "Amanda has completed her inpatient rehabilitation and she's feeling better every day."
The 'Easy A' star spent two months at UCLA Medical Center in California, where she was allegedly diagnosed with schizophrenia and bipolar disorder, after she struck up a small fire in the driveway of a stranger's home in Thousand Oaks, Los Angeles.
Amanda was then moved to the Canyon treatment facility in Malibu at the end of September, where she continued to make improvements, and she is now looking into enrolling in college.
Tamar added: "She's now looking at various colleges with the intention of majoring in fashion design. She's mentioned before she's interested in creating a clothing line."
Amanda's mother Lynn was granted a temporary conservatorship over her daughter in August, but she will continue to have control over her well-being and finances indefinitely.
The statement continued: "Despite the fact Amanda is no longer in a facility, her outpatient treatment is continuing. She's very happy to re-establish the loving relationship with her family that she once shared."