She said the inspiration mainly came from worrying about how her son would be affected by the change.
"My parents were divorced and I know how hard it is," she said during a screening for the film, according to People magazine.
At the time the power couple were calling it quits, Ryan said, "I thought how do you cultivate integrity in a young man? How’s this going to work? I read and read and read, and I talked and talked and talked. I came across this book [The Human Comedy by William Saroyan] and I felt that there was a lot of wisdom in the book -- the great questions that were being asked."
She added, "The grownups and the community didn’t necessarily have all the answers but they were always there for the transitions this young man has to make."
According to IMDB, the movie centers around 14-year-old Homer Macauley and his widowed mother, and his family.
"'ITHACA' is a coming-of-age story about the exuberance of youth, the abruptness of change, the sweetness of life, the sting of death, and the sheer goodness that lives in each and every one of us," the synopsis reads.