In 1967, 19-year-old Susanna (Winona Ryder) feels that "reality is becoming too dense" and is diagnosed with Borderline Personality Disorder. The doctor suggests to her parents that she be committed to the Claymore Hospital, and she spends the next 18 months struggling with her troubled psyche and the bizarre world of the institution. Susanna bonds with several other patients, including Lisa (Angelina Jolie), Polly (Elizabeth Moss), and Georgina (Clea DuVall). As she realizes that Lisa is potentially dangerous and truly needs help, Susanna begins to work harder with her psychiatrist (Vanessa Redgrave) and the nurse on the ward (Whoopi Goldberg). But Susanna soon learns that getting out of the hospital is not as easy as getting in. Girl, Interrupted was based on the autobiography of Susanna Kaysen, who really did spend a year-and-a-half in the McLean Psychiatric Hospital in Belmont, Massachusetts.
by Mark Deming synopsis