Even if Knox decides to eventually finish college, she will have challenges, according to Spector. "She was on a very clear path and she has gotten off that path."
"She will have some catching up to do, not to mention post-traumatic stress," said Spector. "She will have dreams, waking up back in prison again. She will have low trust issues. It will be a long time before she is secure in her own skin."
Prison itself changes a person, according to George Everly Jr., associate professor of psychology at Johns Hopkins Bloomberg School of Public Health.
"Personalities change after enduring stress," he said. "You take someone's freedom away, restrict their activities and what they do. Captivity, in short, is very stressful and there is the possibility that it will have a long-term adverse effect -- not just psychological, but physical health, as well."
Everly said if 100 people are exposed to trauma, only about half of them will develop post-traumatic stress. "Part of the answer is how a person perceives it," said Everly. "If she is truly innocent or believes herself to be innocent, then it is devastating."
Knox's parents said they had hoped her life could return to some normalcy, after celebrating all the missed birthdays and holidays. They have alternated paying her visits in prison, but for the appeals trial, the whole family descended on the small town in Umbria.
"Four years ago I was four years younger, but fundamentally I was younger because I had never suffered before four years ago," Knox told the jury. "Because of four years ago, I didn't know what tragedy was. It was something I would watch on television. That didn't belong to me."
"I want to go home," she said. "I want to go back to my life. I don't want to be punished. I don't want my future to be taken away from me for something I didn't do. Because I am innocent. Just like he is innocent. We deserve freedom. We didn't do anything not to deserve freedom."
Like Knox, Italian student Raffaele Sollecito, now 27, was convicted in 2008 on sexual assault and murder and given a 25-year sentence.
He testified before an appeals court that the when he met Knox, she was "beautiful, happy, vivacious and sweet." He said their short time together was "a beautiful time in my life. Idyllic."
"We were free from everything," he said in court, as Knox's mother and sister burst into tears. "Our only wish was to spend the night cuddling in tenderness. This was our wish."
Knox's family has confirmed that their daughter has broken out in hives and is have difficulty sleeping and eating in prison.
"You don't ever get over it," he said of the prison experience.
"I don't know her personally -- her strengths and weaknesses, being in a strange land in a strange country, even though she is conversational in Italian, but she could experience extreme isolation and it could have an impact on her morale and she could be really traumatized by it," said Kazdin. "Trauma doesn't always come from an acute activity like war or rape."
"The stress of isolation can have an enduring impact on people's immune systems, particularly warding off bacteria and fighting off inflammation and is implicated in a wide range of diseases," he said. "She is at risk."
Normally, when people are under stress, it subsides and life goes back to normal. "But when it carries on, the changes are real," said Kazdin. "Young children who are stressed all the time have more disease and die younger. This is not tiny stuff. Will she suffer that?"
"Youth gives her body resilience, but she has less experience in coping skills," he said. "The mental and physical go together. You can get depression, trauma, stress and illness in the normal process of enduring stress and isolation."