Susana Kaysen is 18 years old at the beginning of her memoir. She is a bright but troubled teenager with a surprising breadth of life experience. At this age, Kaysen has already abandoned school, had an affair with her high school English teacher, and half-heartedly attempted suicide. During a fateful consultation with the doctor who will usher her into nearly two years of hospitalization, Kaysen’s overriding emotion is exhaustion. She signs herself into McLean Hospital with a sense, at least initially, of relief.

Kaysen narrates Girl, Interrupted in a cool, dispassionate voice, sketching the characters and scenes that illustrate life in a mental hospital for the affluent in the late 1960s. The nearly emotionless narration reflects both the detachment Kaysen feels from life as an adolescent, and a desire to leave certain conclusions to her readers. As she explores the nature of sanity and social conformity and the manner in which they interrelate, Kaysen avoids outright indictment of the system that confined her. The scenes she narrates are complicated and offer no easy lessons.

In the course of her time at McLean, Kaysen learns about the nature of mental illness, the cruelty and compassion of other people, and the obstacles that women face in society. She draws connections among the various stigmas she faces as a young woman. As an adolescent, petty rebellions and refusal to follow rules alarm her parents. Later, at a short-lived typing job, unconcealed sexism in the workplace shocks Kaysen. Once a patient at McLean, she feels the discomfort with which outsiders greet her and the other patients, an experience repeated when she tries to find employment outside the hospital.

The adult Kaysen confesses to fighting a mild revulsion toward the mentally ill, born of fear that she might backslide into that “parallel universe.” She hopes never to return to the sad place where mental instability collides with a society quick to isolate it.