Dugard's case is complicated by the fact that she has two daughters, ages 15 and 11, with her captor.
"You can never erase those 18 years…but what you can do is create a kind of new normal and you can help her live a positive and productive life," Allen said.
He said it's also important for Dugard to play a role in her daughters' healing.
"Their captor who had limited their access to the world… but this was dad," he said. "It's important again to reinforce with them that they've done nothing wrong. Jaycee will play a key role in this. It's going to take patience and time to help these children catch up."
For Hornbeck's family, healing came through therapy.
"It gave Shawn a safe place to tell us things he had done in captivity and it gave us a safe environment to react," said Pam Akers. "If we wouldn't have had all of that ... I don't think it would have been successful. Individual and group therapy is one of the things Jaycee and her family should do."
Dugard's step-father told "GMA" Monday that she was experiencing feelings of guilt. Allen said that's not unusual for kidnapping victims.
"It is a slow, patient process, but first you reintroduce Jaycee to her parents," he said. "You emphasize the importance of unconditional love."
Shawn Hornbeck's parents concurred.
"I'm sure there's so many emotions complicated by the fact she has two young daughters," Craig Akers said. "I'm sure that she's confused and uncertain, probably wondering if people are going to blame her."
"We have to make sure they love her no matter what," he added. "She has to know what happened wasn't her fault. You have to make sure she has no thoughts like that at all...she's not responsible for any of it."
Today, Shawn's parents say he's doing well and is a typical high school senior, dating, working part time and starting to look at colleges.
"We're very grateful we have this opp to send a message of hope to families that have children out there," Craig Akers said. "There are more people like this…some perhaps in a situation like Jaycee.. We want to get our message out there that it's ok...your family loves you no matter what."