Girl Interrupted starts with a girl being committed to a mental institution for attempting suicide, even though she denied that this was her intent. She is diagnosed with borderline personality disorder and is subject to stay for 18 months. She becomes very comfortable with the other "crazy" girls staying there. Their problems include pathological lying, sexually abuse, burns by fire, sociopath, not eating in the presence of others, and an escaper. She falls into the control of one of the wildest girls in the bunch. Her complication is deciding whether to fall in her ways or to get out of the institution.
In general, the movie shows women at their weak points, when they are down and out. It also shows their struggle in overcoming this and this is empowering. While not all of the girls make it, it shows that not everyone in society has it made and that there are problems in the world that must be overcome.
This could be considered a feminist film in many ways. Angelina's way of carrying herself and demanding authority, whether in a hospital or not, shows that power is attainable anywhere.
While many parts of the movie are eye-opening, I enjoyed the film and would watch it again.
More about the book can be found on the internet sites of Wikipedia, the Internet Movie Database, Bookrags, and Movieweb.