Since her conviction in the murder of British roommate Meredith Kercher in 2007, Knox has said that she longs to go home and daydreams of catching up on Harry Potter movies and lying in the grass of her Seattle back yard.
After spending four years in a cramped cell in an Italian prison, Knox appeared elated but emotional as an appeals court in Perugia overturned her 26-year sentence.
But her pale face and thinning hair reveal the toll prison life has taken on the young woman psychologically. Even before her fate was sealed, cameras showed her nervous breathing and a face buried in hands, ready for the heaving tears that would follow.
"She still has had a horrific experience and her sense of trust in police and in people is gone," said Ann Rosen Spector, a clinical psychologist from Philadelphia. "Some people may still believe she did it and will treat her differently. Her name is well known.
"It will take time to get back to normal," said Spector, who specializes in depression, stress and anxiety issues. "She lost four years of her life."
Knox was found guilty of slandering Perugia police for claiming during her trial that the police abused her and cuffed her on the back of her head.
In the past months, the carefree college student has seemed increasingly more fragile and less naive. Her parents, Edda Mellas and Curt Knox, have told ABC that she has broken out in hives and is having trouble sleeping and eating.
Her father told CNN recently that, "We'll take her home and find out what kind of trauma she's experienced in prison -- even if she wants to talk."
Knox arrived in Italy in 2007, a 20-year-old college student eager to learn another culture, thousands of miles from her Seattle home. But only months into the first semester, her apartment roommate, Kercher, was brutally murdered.
Knox and her then-Italian boyfriend Raffaele Sollecito were arrested for the murder, and a jury in Perugia, Italy, eventually found them guilty. Sollecito's conviction was also overturned.
The American press has been sympathetic to the kooky, free-spirited Knox, who is now fluent in Italian. But local accounts have been searing, calling her an "angel face with icy eyes"
"This is really traumatic for her," said Judy Kuriansky, an adjunct professor of clinical psychology at Columbia University's Teachers College. "She is going to be just as wrecked as Casey Anthony -- the trial and the lurid details -- the accused sex play and throat slashing and a drug-filled orgy. This will continue to follow her forever."
"There is no way she will have a normal life," said Kuriansky. "No matter where she goes, they will think of her as Foxy Knoxy."
Knox has also faced harsh judgment from her murdered roommate's family. John Kercher contended the trial was fair and was critical of the way the press has given Knox "celebrity" status.
"I lost a friend in the most brutal inexplicable way," Knox said in her statement to the jury. "My trust, my full trust in the police has been betrayed. I had to face absolutely unjust charges, accusations and I'm paying with my life for something that I did not commit."